In response to both the election of Barack Obama in 2008 and the backlash in favor of Donald Trump in 2016, analysts and commentators have focused mostly on racial attitudes on the right. Both scholarship and journalistic accounts of American politics have drilled down on the increased opposition to immigration and high levels of racial resentment among Obama opponents and Trump supporters.

But few have investigated the countervailing trend on the left, the increasing racial liberalism of Democratic voters, which I’ve been thinking about for a while.

Though Mr. Obama’s presidency ended up being defined in many ways by America’s reaction to his race, he carefully avoided racially liberal appeals during his original campaign, even taking the time to criticize the purported excesses of campus liberalism. Mr. Obama had begun his national political career with a speech at the Democratic convention in 2004, declaring that “there’s not a black America and white America and Latino America and Asian America; there’s the United States of America.” During his 2008 campaign, to give just one example, he turned down an invitation to Tavis Smiley’s State of the Black Union, an event Hillary Clinton attended.

During her 2016 campaign, Mrs. Clinton invoked concepts like intersectionality, white privilege, implicit bias and systemic racism. She warned of “deplorables,” while Mr. Obama once gave a speech arguing that “to wish away the resentments of white Americans, to label them as misguided or even racist, without recognizing they are grounded in legitimate concerns” was something that “widens the racial divide, and blocks the path to understanding.” According to the American National Election Studies 2016 survey, Democrats perceived Mrs. Clinton as more racially liberal than they had perceived Mr. Obama in 2012, when his strategy was not notably different.