With a tweeted attack on four minority congresswomen this week, President Trump made clear that his reelection campaign will feature the same explosive mix of white grievance and anti-immigrant nativism that helped elect him.

Trump’s combustible formula of white identity politics has already reshaped the Republican Party, sidelining, silencing or converting nearly anyone who dares to challenge the racial insensitivity of his utterances. It also has pushed Democratic presidential candidates sharply to the left on issues such as immigration and civil rights, as they respond to the liberal backlash against him.

Left unknown is whether the president is now on the verge of more permanently reshaping the nation’s political balance — at least until long-term demographic changes take hold to make nonwhite residents a majority of the country around 2050.

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