Support in polls for racial preferences varies wildly depending how the issue is framed. Yet when racial-preference systems have been put directly to voters in statewide referendums with real consequences, majorities have almost always said no. Last week Washington state’s liberal electorate continued that trend, narrowly overruling the Legislature’s bid to reintroduce preferences in public education and employment.

In 1998 the Evergreen State voted by a 16-point margin to ban racial preferences. But this spring the state’s...