People are always changing their minds, day to day. But over the past 20-odd years one group has shifted to an astounding degree: highly educated white Democrats. I’m not sure I understand why this group has undergone such a transformation, but it has, and the effects are reshaping our politics.

The easiest way to describe the shift is to say that educated Democrats have moved steadily to the left. In 1994, only about a sixth of Democrats who had gone to graduate school said they were consistently liberal. In 2015, more than 50 percent did. In 1994, only 12 percent of Democrats with college degrees said they were consistently liberal. Twenty-one years later, 47 percent did, according to the Pew Research Center.

One of the results is that, as my colleague Thomas B. Edsall put it this week, there are now three Democratic Parties. The most moderate faction is the most nonwhite and focuses on pocketbook issues like jobs and taxes. The most left-wing segment is the most populated by whites. It focuses on issues like abortion, global warming, immigration and race and gender equity.

To say that white educated Democrats have moved left is true, but it’s not the essential truth. The bigger truth is that this segment is now more likely to see politics through a racial lens. Racial equity has become the prism through which many in this group see a range of other issues.