President Trump’s tweet attacks on members of Congress of color, from “The Squad” to Representative Elijah Cummings, have made it clear that fanning the flames of white racial resentment is central to his politics and re-election strategy.

For decades, some left-leaning strategists stifled their candidates’ response to dog whistles for fear of alienating whites who they thought might otherwise support Democrats. Today, there is still great ambivalence about making the fight against racism a defining issue in the 2020 election.

But the cold hard truth is that our elections are already racialized — and have been ever since Congress codified the concept of racial equality in the 1960s by passing the 1964 Civil Rights Act and the 1965 Voting Rights Act.

With every attack, Democrats are now speaking out. And decades of election data on voter behavior show that Democrats are on firm ground in making the president’s overt racism a prominent campaign issue. That data shows that there are enough white voters for Democrats to defeat a president stirring racial resentment. It might, in a tight race, be barely enough — but enough. And the math gets more promising in 2020 when the electorate will be more racially diverse than at any previous time in United States history. […]