In this Nov. 13, 2014 file photo, Sen. Elizabeth Warren (D-Mass.) speaks during a news conference on Capitol Hill in Washington, after Senate Democrats voted on leadership positions for the 114th Congress. (AP Photo/Evan Vucci, File)

Republicans have been a party divided for a few years now, with the tea party feuding with the establishment in hopes of guiding the party down a more conservative path.

A byproduct of this was that many Republicans decided they didn't much like their own political party. And so, for years, the Republican Party's image lagged behind the Democratic Party's.

That's not really the case anymore -- and it's in large part because Democrats have learned to loathe themselves just like Republicans.

A new Pew Research Center poll shows Democrats are now about as down on their own brand as Republicans are. While 78 percent of Republicans have a favorable view of the GOP, 76 percent of Democrats like their own political party.

That 76 percent figure is a two-year low (and probably much longer) and is about 10 points lower than usual. The GOP, meanwhile, has seen its self-esteem -- if that's the correct word -- rise from 69 percent in early 2013 to 78 percent today. So while that "self-esteem gap" was 18 points in Democrats' favor in January 2013, it's now two points in the GOP's favor.

These aren't massive shifts, but they do suggest growing uneasiness among Democrats with their party's performance. And this isn't the first poll to suggest it, either.

A Washington Post-ABC News poll conducted just before the 2014 election showed the Democratic brand hitting a three-decade low, at 39 percent favorable. It also showed little difference in self-evaluations of the parties, with 77 percent of Democrats approving of their own party and 74 percent of Republicans approving of theirs.

But while the GOP's self-loathing is still very much about an intra-party split, that kind of split isn't really evident on the Democratic side -- no matter how much we all like to speculate about Elizabeth Warren vs. Hillary Clinton.

Instead, the Democrats' increasingly dim view of their own side seems to be more about a kind of general malaise -- perhaps due to President Obama's long-standing unpopularity and the lack of results in recent years, and perhaps because their party just lost control of Congress.

No matter the cause, though, if it persists, it's not good for party unity.