The Republican Party is much more ideologically pure than the Democrats — and than the Republican Party of 18 years ago. Then, 39.5 of Republicans identified as conservative or extremely conservative; now, 47.7 percent — almost half — do. Only 6 percent identify as liberal…

Trump, too, has grown more conservative in recent years, and his presidency reflects that. He’s made goading the political opposition a central part of his strategy in office and it remains a core part of his appeal. Whether the party is shedding more moderate members at a significant rate, it’s obviously true that the party’s ideology has become more homogeneous than it was in the past.

A president who appeals to that homogeneity is likely to fare well.