German ancestry is #1, English ancestry is #2

[Del Tachi]

I wonder what’s driving the recent uptick in English identification? More people taking DNA tests and realizing they’re not Irish? Less people identifying as American? I answer English on the census and I know most people from my hometown have English ancestry but the ACS shows self English ID at less than 15%.

English ancestry is so ubiquitous among White Americans that no one considers it very notable, so you're liklier to have White people know about/identity with their more "exotic" Irish or German heritage.  Whites who literally don't care just put "American."  

I believe Utah is the most "English" state in America, although that is almost certainly a function of Mormons' interest in genealogy and family history.  I would not expect Mormon ancestry to differ that much from White Americans, so they may be a good group to look at.  

[Del Tachi]

It's kind of ironic that the vast majority of Americans with German ancestry vote Republican while that party wouldn't get 20% of the vote here. The Republican Party is pretty much seen as a joke here, even among a lot of conservatives.

That's not "ironic" unless you think politics is somehow hereditary LOL