Around 40,000 people join an anti-racial discrimination rally in Boston on Aug. 19, 2017, a week after a violent white supremacist rally in the Virginia college town of Charlottesville. (Kyodo) ==Kyodo

Counterprotesters hold signs and chant at the Statehouse before a planned "Free Speech" rally by conservative organizers begin on the adjacent Boston Common, Saturday, Aug. 19, 2017, in Boston. Police Commissioner William Evans said Friday that 500 officers, some in uniform, others undercover, would be deployed to keep the two groups apart. (AP Photo/Michael Dwyer), APTOPIX

A counterprotester, left, confronts a professed supporter of President Donald Trump at a "Free Speech" rally by conservative activists on Boston Common, Saturday, Aug. 19, 2017, in Boston. Thousands of leftist counterprotesters marched through downtown Boston on Saturday, chanting anti-Nazi slogans and waving signs condemning white nationalism ahead of a rally being staged by conservative activists a week after a Virginia demonstration turned deadly. (AP Photo/Michael Dwyer), APTOPIX

A counterprotester holds a photo of Heather Heyer on Boston Common at a "Free Speech" rally organized by conservative activists, Saturday, Aug. 19, 2017, in Boston. Heyer was killed last Saturday when a car, allegedly driven by James Alex Fields Jr., that plowed into a group of people during protests in Charlottesville, Va. (AP Photo/Michael Dwyer), APTOPIX

Organizers stand on the bandstand on Boston Common during a "Free Speech" rally staged by conservative activists, Saturday, Aug. 19, 2017, in Boston. Counterprotesters stand along barricades ringing the bandstand. (AP Photo/Michael Dwyer)

Organizers depart a "Free Speech" rally staged by conservative activists on Boston Common, Saturday, Aug. 19, 2017, in Boston. One of the planned speakers of a conservative activist rally that appeared to end shortly after it began says the event "fell apart." Dozens of rallygoers gathered Saturday on Boston Common, but then left less than an hour after the event was getting underway. Thousands of counterprotesters had also gathered. (AP Photo/Michael Dwyer)

Police prepare to escort organizers from the bandstand on Boston Common after a "Free Speech" rally staged by conservative activists, Saturday, Aug. 19, 2017, in Boston. One of the planned speakers of a conservative activist rally that appeared to end shortly after it began says the event "fell apart." Dozens of rallygoers gathered Saturday on Boston Common, but then left less than an hour after the event was getting underway. Thousands of counterprotesters had also gathered. (AP Photo/Michael Dwyer)

Counterprotesters stand on the periphery of a "Free Speech" rally staged by conservative activists on Boston Common, Saturday, Aug. 19, 2017, in Boston. One of the planned speakers of a conservative activist rally that appeared to end shortly after it began says the event "fell apart." Dozens of rallygoers gathered Saturday on Boston Common, but then left less than an hour after the event was getting underway. Thousands of counterprotesters had also gathered. (AP Photo/Michael Dwyer)

Boston Police Commissioner William Evans watches counterprotesters near a "Free Speech" rally staged by conservative activists, Saturday, Aug. 19, 2017, in Boston. Dozens of rallygoers gathered Saturday on Boston Common, but then left less than an hour after the event was getting underway. Thousands of counterprotesters had also gathered. TV cameras show police vans escorting participants away, and angry counterprotesters scuffled with armed officers trying to maintain order. (AP Photo/Michael Dwyer)

Police move toward a counter-protester, right, near a "Free Speech Rally" staged by conservative activists, Saturday, Aug. 19, 2017, in Boston. (AP Photo/Michael Dwyer)

A man wearing a T-shirt bearing the name of President Donald Trump, right, is hit by a flying plastic bottle of water near a "Free Speech" rally staged by conservative activists, Saturday, Aug. 19, 2017, in Boston. Counterprotesters marched through the city to historic Boston Common, where many gathered near a bandstand abandoned early by conservatives who had planned to deliver a series of speeches. Police vans later escorted the conservatives out of the area, and angry counterprotesters scuffled with armed officers trying to maintain order. (AP Photo/Michael Dwyer), APTOPIX

A man wearing a T-shirt bearing the name of President Donald Trump, right, argues with a counterprotester after being hit by a flying plastic bottle of water near a "Free Speech" rally staged by conservative activists, Saturday, Aug. 19, 2017, in Boston. An estimated 15,000 counterprotesters marched through the city to historic Boston Common, where many gathered near a bandstand abandoned early by conservatives who had planned to deliver a series of speeches. Police vans later escorted the conservatives out of the area, and angry counterprotesters scuffled with armed officers trying to maintain order. (AP Photo/Michael Dwyer)

A man wearing a T-shirt bearing the name of President Donald Trump, center, argues with counterprotesters after being hit by a flying plastic bottle of water near a "Free Speech" rally staged by conservative activists, Saturday, Aug. 19, 2017, in Boston. An estimated 15,000 counterprotesters marched through the city to historic Boston Common, where many gathered near a bandstand abandoned early by conservatives who had planned to deliver a series of speeches. Police vans later escorted the conservatives out of the area, and angry counterprotesters scuffled with armed officers trying to maintain order. (AP Photo/Michael Dwyer)

Police tussle with counterprotesters near a "Free Speech" rally staged by conservative activists, Saturday, Aug. 19, 2017, in Boston. An estimated 15,000 counterprotesters marched through the city to historic Boston Common, where many gathered near a bandstand abandoned early by conservatives who had planned to deliver a series of speeches. Police vans later escorted the conservatives out of the area, and angry counterprotesters scuffled with armed officers trying to maintain order. (AP Photo/Michael Dwyer)

Police escort away a counterprotester near a "Free Speech" rally staged by conservative activists, Saturday, Aug. 19, 2017, in Boston. An estimated 15,000 counterprotesters marched through the city to historic Boston Common, where many gathered near a bandstand abandoned early by conservatives who had planned to deliver a series of speeches. Police vans later escorted the conservatives out of the area, and angry counterprotesters scuffled with armed officers trying to maintain order. (AP Photo/Michael Dwyer), APTOPIX

A woman covers her ears as police officers line the street near a "Free Speech" rally staged by conservative activists on Boston Common, Saturday, Aug. 19, 2017, in Boston. Counterprotesters marched through the city to historic Boston Common, where many gathered near a bandstand abandoned early by conservatives who had planned to deliver a series of speeches. Police vans later escorted the conservatives out of the area, and angry counterprotesters scuffled with armed officers trying to maintain order. (AP Photo/Michael Dwyer)

A counterprotester, part of a small group who remained on the street hours after a "Free Speech" rally was staged by conservative activists, scuffles with a security guard and police, Saturday, Aug. 19, 2017, in Boston. (AP Photo/Michael Dwyer), APTOPIX

Police escort an injured man who was assaulted while arguing with counterprotesters long after a "Free Speech" rally was staged by conservative activists, Saturday, Aug. 19, 2017, in Boston. (AP Photo/Michael Dwyer)

Police try to calm an injured man who was assaulted while arguing with counterprotesters long after a "Free Speech" rally was staged by conservative activists, Saturday, Aug. 19, 2017, in Boston. (AP Photo/Michael Dwyer)

Counterprotesters hold signs at a "Free Speech" rally by conservative activists on Boston Common, Saturday, Aug. 19, 2017, in Boston. Thousands of demonstrators marched Saturday from the city's Roxbury neighborhood to Boston Common, where the "Free Speech Rally" is being held. (AP Photo/Michael Dwyer)

Counterprotesters clash with police following a "Free Speech" rally staged by conservative activists on Boston Common, Saturday, Aug. 19, 2017, in Boston. One of the planned speakers of a conservative activist rally that appeared to end shortly after it began says the event "fell apart." Dozens of rally goers gathered Saturday on Boston Common, but then left less than an hour after the event was getting underway. Thousands of counterprotesters had also gathered. (AP Photo/Michael Dwyer)

Counter-Protesters of the Boston 'Free Speech' Rally march towards Boston Commons on August 19, 2017. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Counter-Protesters of the Boston 'Free Speech' Rally march towards Boston Commons on August 19, 2017. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Counter-Protesters of the Boston 'Free Speech' Rally march towards Boston Commons on August 19, 2017. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Counter-Protesters of the Boston 'Free Speech' Rally march towards Boston Commons on August 19, 2017. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Counter-Protesters of the Boston 'Free Speech' Rally march towards Boston Commons on August 19, 2017. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Counter-Protesters of the Boston 'Free Speech' Rally march towards Boston Commons on August 19, 2017. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

police patrol the Boston 'Free Speech' Rally march and counter-demonstrators on August 19, 2017, in Boston. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Police patrol the Boston 'Free Speech' Rally march and counter-demonstrators on August 19, 2017, in Boston. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Counter-protesters of the Boston 'Free Speech' Rally clash with police as they are moved back at Boston Commons on August 19, 2017, in Boston. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Counter-protesters of the Boston 'Free Speech' Rally clash with police as they are moved back at Boston Commons on August 19, 2017, in Boston. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Counter-protesters of the Boston 'Free Speech' Rally march towards Boston Commons on August 19, 2017, in Boston. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Counter-protesters of the Boston 'Free Speech' Rally march towards Boston Commons on August 19, 2017, in Boston. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Counter-protesters of the Boston 'Free Speech' Rally march towards Boston Commons on August 19, 2017, in Boston. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Counter-protesters of the Boston 'Free Speech' Rally march towards Boston Commons on August 19, 2017, in Boston. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Counter-protesters of the Boston 'Free Speech' Rally clash with police as they are moved back at Boston Commons on August 19, 2017, in Boston. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Counter-protesters of the Boston 'Free Speech' Rally clash with police as they are moved back at Boston Commons on August 19, 2017, in Boston. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Free Speech demonstrators (C) flee after confronting counter-protesters at the Boston 'Free Speech' Rally march on August 19, 2017, in Boston. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Counter-protesters of the Boston 'Free Speech' Rally march towards Boston Commons on August 19, 2017, in Boston. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Counter-protesters of the Boston 'Free Speech' Rally march towards Boston Commons on August 19, 2017, in Boston. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Counter-protesters of the Boston 'Free Speech' Rally march towards Boston Commons on August 19, 2017, in Boston. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Counter-protesters of the Boston 'Free Speech' Rally march towards Boston Commons on August 19, 2017, in Boston. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Counter-protesters of the Boston 'Free Speech' Rally march towards Boston Commons on August 19, 2017, in Boston. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Counter-protesters of the Boston 'Free Speech' Rally march towards Boston Commons on August 19, 2017, in Boston. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Counter-protesters of the Boston 'Free Speech' Rally march towards Boston Commons on August 19, 2017, in Boston. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Counter-Protestors Boston 'Free Speech' march are arrested in Bolyston Street near the Boston Commons on August 19, 2017, in Boston. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Police try to block counter-protesters of the 'Free Speech' Rally on August 19, 2017, in Boston. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride

Police try to block counter-protesters of the 'Free Speech' Rally on August 19, 2017, in Boston. Thousands of anti-racism demonstrators flooded the streets of Boston Saturday, dwarfing a gathering of white nationalists in the city, triggering scuffles with police but avoiding the serious violence that marred a similar event a week earlier in Virginia. / AFP PHOTO / Ryan McBride