A fascinating poll because of how it defies expectations. Normally when you see a sharp downturn by one party on a national-satisfaction question like this, there’s an obvious partisan explanation. Democrats suddenly aren’t proud to be American? (Less proud than before, I mean.) Well, naturally — there’s a Republican president now. They’re viewing the country through that lens. The reverse is true for Republicans, one would assume. Surely their pride in being American has increased since the electorate chose to replace Barack Obama with Trump.

And we do see both of those effects here. Democratic opinion of America is down and Republican opinion is up since Trump took office.

The fascinating part is the trendline for each party *before* Trump was sworn in.

Overall just 47 percent of Americans say they’re extremely proud of their nationality, the first time in 18 years of polling by Gallup that that number has dipped below 50 percent. Most of the damage in that decline is being done by Democrats, of course. They’ve dropped 11 points since last year, obviously a reaction to POTUS and his undoing of various Obama policies.

But look at the decline before the Trump era began. Democrats lost as much ground on the “extremely proud” question between 2013 and 2016, the heart of Obama’s second term, as they have since. Conversely, despite their strong antipathy to O, Republican pride in being American has barely budged since his second term began. It’s up since Trump took office, but only negligibly. When you look at voters by ideology instead of party the contrast is even more dramatic. The share of self-described conservatives who are “extremely proud” to be American is exactly the same now as it was in 2013, 65 percent. (Republican stasis despite having a Republican in the White House speaks volumes about the party’s own misgivings about some of Trump’s behavior.) The share of self-described liberals, however, has fallen off a cliff — from 51 percent five years ago to 23 percent now. More than half of liberals have lost their pride. And in this case, most of the decline happened on Obama’s watch. By 2016, just 36 percent of liberals were extremely proud to be American, down 15 points from the start of O’s second term. They’ve dropped a further 13 points since then.

Most interesting of all, Gallup doesn’t really even attempt to explain the decline. Normally a new poll like this one gets some analytical spitballing in the pollster’s write-up suggesting possible causes for the fluctuations in the numbers over time, but the most Gallup offers is “National pride may be just one of a growing number of issues — including opinions about guns, labor unions and the environment — for which party loyalties are pushing Democrats and Republicans to adopt divergent views.” That’s fine but those issues are evergreen. Aren’t there more obvious explanations for the recent liberal slide — ones that rhyme with “Shmillary Shminton,” say? Liberals were the only major faction in American politics to absorb a double defeat in the last election, first having to watch as the underwhelming establishmentarian beat back Berniemania and then having to watch as her supposed big asset, “electability,” failed her against a Republican who was eminently beatable. Hillary was already the presumptive nominee by 2015, which may explain the liberal/Democratic fade in the latter half of O’s term. By 2016, with Bernie finally vanquished, liberal morale sunk even lower. Trump’s victory naturally only accelerated it. It has to be an election thing, doesn’t it?

Although maybe not entirely. The Republican takeover of the Senate in 2014 might have damaged Democratic pride in being American too, as that spelled the end effectively of Obama’s presidency. Not only would liberal legislation no longer pass either chamber of Congress, Obama’s nominees would now be subject to a Republican veto.

Whatever the explanation, until recently the share of Americans who were “extremely proud” of their country was freakishly stable despite the political volatility of the times. Starting midway through Bush’s dreary second term and extending all the way to midway through Obama’s, the number hovered at 57-58 percent. That period includes two presidential elections. Not until the rise of Trump — and Clinton — did things start to turn south, and even then really only on the left. Another reason to think that the next Dem nominee will be more progressive, to bring some of those disaffected liberals back into politics.

Exit question: Could it be that 2013 is a flawed benchmark for gauging “normal” Democratic pride in being American? Pride on the left might have may been unusually high that year because the party was celebrating another Obama victory the year before. But if that’s the case, how to explain that pride among the overall population was flat that same year? It’s not like Republican pride in the country hadn’t tanked after Romney’s loss to offset any Democratic increase, as the graph above proves.