People determined to stand against racism can raise concerns about groups that espouse hate and problems like the racial achievement gap in schools without smearing huge numbers of Americans, many of whom might otherwise be Democrats by temperament.
Liberals can act as if they’re not so certain — and maybe actually not be so certain — that bigotry motivates people who disagree with them on issues like immigration. Without sacrificing their principles, liberals can come across as more respectful of others. Self-righteousness is rarely attractive, and even more rarely rewarded.
Self-righteousness can also get things wrong. Especially with the possibility of Mr. Trump’s re-election, many liberals seem primed to write off nearly half the country as irredeemable. Admittedly, the president doesn’t make it easy. As a candidate, Mr. Trump made derogatory comments about Mexicans, and as president described some African countries with a vulgar epithet. But it is an unjustified leap to conclude that anyone who supports him in any way is racist, just as it would be a leap to say that anyone who supported Hillary Clinton was racist because she once made veiled references to “superpredators.”