Op-ed by Stanley B. Greenberg @ NYTimes.com, June 18

Mr. Greenberg is a Democratic pollster.

[....] Well, Mr. Trump’s base strategy is producing precisely that kind of enthusiasm gap in the polls I am conducting for Democracy Corps and its partners, the Women’s Voices Women Vote Action Fund and the American Federation of Teachers. Mr. Trump’s strategy is to continue to build support with the Tea Party supporters and evangelicals who make up a plurality of those who identify as Republicans, but they are by no means the whole of the party. And Mr. Trump shows as much interest in winning over those less enthusiastic Republicans as he does in winning independents and Democrats — which is to say, not much.

Mr. Trump’s base strategy brands the Republican Party as sexist, racist, xenophobic and anti-immigrant, which magnifies the anti-Trump reaction among Democrats. But it also leaves a tenth who are conservative Catholics and a fifth who are nonreligious conservatives more tentative in their support of the Republican Party — and it pushes away the quarter of Republicans who remain ideologically moderate. The harder the president bangs these drums, the more Democrats become enraged and a segment of Republicans gets demoralized. The more he trashes and defeats his Republican opponents in primaries, the more these voters may contemplate different political options [.....]