Samson Racioppi, a candidate for Massachusetts’ 6th congressional district as a Libertarian, gets into a heated verbal exchange with members of a counter-protester group during the Rally to Denounce Political Violence on Saturday at the State House. Minutes earlier, Racioppi had implored the counter-protesters to join the nearby rally, but was chided for prevaricating on whether the death of Heather Heyer, the victim of a hit-and-run attack by a white supremacist in Charlottesville, Va., was an act of political hatred.