A few days after the assassination of the Rev. Dr. Martin Luther King Jr., the Republican governor of Maryland, Spiro T. Agnew, strode into a conference room in downtown Baltimore. In the hours after King’s death, violence had broken out in the city; along with Washington and Chicago, it was soon occupied by the United States Army. In response, Agnew called together the black community on April 11 for “a frank and far-reaching discussion.”

It wasn’t a discussion. It was a trap. The governor tore into the crowd for standing by while rioters ransacked stores and set cars on fire. They claimed to speak for racial harmony, he boomed, but when the violence began, “You ran.”

Within minutes, most of the audience members had stormed out; at the door, they found a scrum of reporters, whom Agnew had tipped off. Within hours, Agnew’s confrontation was national news; within days, this once-obscure first-time governor was being assailed as a racist by the left and hailed as a rising star in the Republican Party. That summer, Richard Nixon picked him as his running mate.

Fifty years later, we remember Spiro Agnew, if at all, as a bumbling vice president who later pleaded no contest to tax evasion, resigned in disgrace and ended his career funneling military surplus to Saddam Hussein and Nicolae Ceausescu. But his rise during the spring of 1968 is instructive because suddenly it feels so familiar: a white Republican who claimed to speak against radicalism and for the forgotten man, but in fact ran on exacerbating racial animosity. Far from a bit player, Agnew marked a watershed moment in American history, when the Republican Party committed itself to the shift from being the party of Lincoln to the party of white racial backlash.