Writing at Power Line, regular Steven Hayward posts a couple of charts from a July 2 Gallup survey of American's pride in their country. Who isn't extremely proud to be an American? Democrats, of course.
The real kicker is in the second chart. Trump only accounts for a bit of Democrats' pride-lack. Even during the Obama years a maximum of 56% of Democrats were extremely proud of America. By the time Obama left office, only 44% of Democrats were extremely proud of America.
By contrast, most Republicans are extremely proud of America and continued to be so during the Obama administration. In fact, during all 8 Obama years a greater percentage of Republicans than Democrats were proud of our country!
True fact. Across the entire span of years (2001-2019) included in Gallup's chart, at no time did the percentage of Democrats extremely proud of America even come close to that of Republicans.
Admittedly, the gap is wider today than formerly and likely Trump can take credit or blame (choose one) for that increase. I choose "credit," he trolls Dems perfectly and they deserve it richly.
Philosophical Aside: These numbers have "face validity." Republicans historically represent those Americans for whom our nation's particular combination of opportunities and constraints "works." Democrats represent those for whom, for whatever reason, it doesn't or for whom it works "too well," creating guilt.