ONE IN FIVE…. Perhaps the most striking result in the Washington Post/ABC News poll released yesterday had to do with the relative size of the parties: “Only 20 percent of adults identify themselves as Republicans, little changed in recent months, but still the lowest single number in Post-ABC polls since 1983.”

Newt Gingrich was asked about the number, and blasted the poll. ABC News polling director Gary Langer had a compelling response.

Former House Speaker Newt Gingrich had some pretty harsh criticism of our latest poll today, charging in a radio interview that it was “deliberately rigged.” He’s entitled, of course, to his opinion. But not to a distortion of the facts.

What’s his gripe? Gingrich made the comment on our Salt Lake City affiliate, KSL-AM, when asked about our finding that only 20 percent of Americans now identify themselves as Republicans, the fewest since September 1983 in ABC News/Washington Post polls. His reply:

“Well, it tells me first of all that the poll’s almost certainly wrong. It’s fundamentally different from Rasmussen. It’s fundamentally different from Zogby. It’s fundamentally different from Gallup. It’s a typical Washington Post effort to slant the world in favor of liberal Democrats.”

We’ve heard it before, from both sides: Democrats jump on data they don’t like, Republicans do the same. The reality is that this poll, as all our work, was produced independently and with great care, including the highest possible methodological standards. And contrary to Gingrich, it happens to be in accord with most other recent good-quality surveys measuring political partisanship.

And that’s really the key here. The latest CBS News poll found 22% identify themselves as Republicans. The latest AP poll found 21%. Ipsos/McClatchy put the number at 19%. Gallup had the highest total for the GOP, at 27%, but the Pew Forum study had it at 23%, while NBC/WSJ found 18%.

Average those together, and we find about 21% of the public are self-identified Republicans. What did the Post/ABC find? 20%.

Are there poll outliers that deserve skepticism? Absolutely, but this doesn’t appear to be one of them.

Gingrich may not like the results, but that doesn’t make them wrong, and it certainly doesn’t make the poll “slanted” or “deliberately rigged.” There’s no conspiracy necessary: the Republican brand is suffering badly, and it has yet to recover from the Bush/Cheney era.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.