Conventional wisdom, that amalgamation of bland center-left opinion that permeates much of what you read and see in political coverage (think David Gergen and Nina Totenberg), has had a rough go of it this primary cycle. CW’s erroneous analysis and assumptions (e.g., the anti-Bain attacks would bolster Newt Gingrich, most voters are amenable to the president’s class envy argument) have been matched only by the right-wing blogs’ track record of serial errors (e.g. Herman Cain was for real, Texas Gov. Rick Perry was the answer to the right’s woes, Rick Santorum should be ignored). In fact, in many instances the left-center and the right-wing blogs have made precisely the same errors.

Take the notion that Rick Santorum should get out of the race so Gingrich can wrest the nomination from Mitt Romney. The Post reports:

“Well, Rick Santorum ... is a factor in this race,” Gingrich’s Florida campaign co-chairman, Bill McCollum, said on CNN on Monday afternoon. “If he weren’t in it, we would clearly be beating Romney right now.”

“I think that Rick is not the player long haul at all,” McCollum added. “I don’t know how long he stays in it. He’s a friend. I know him well. But I think a vote for Rick is simply ... a vote that’s wasted at this point.”

Recent polls show Gingrich trailing former Massachusetts governor Mitt Romney (R) by double digits in Florida, with one survey showing Romney ahead by as much as 20 points. That means that if Santorum were to drop out, it’s not a sure bet that Gingrich would be able to make up the deficit.

On the other hand, an NBC News/Marist poll conducted last week backs up the Gingrich camp’s claim. In that survey, Romney takes 42 percent among likely Florida GOP primary voters compared with 27 percent for Gingrich and 16 percent for Santorum.

But that’s plain wrong. The NBC News/Marist poll says explicitly: “If Santorum were not in the competition, Romney would still be ahead of Gingrich, 49% to 33%. Santorum’s supporters divide when asked whom their second choice candidate is. 36% of Santorum’s backers choose Gingrich while 35% are for Romney.”In fact, when you look at just about any of the reputable national polls, Santorum voters are evenly divided when asked their second choice.

Here’s another CW doozy: Gingrich can really make a lot of trouble at the Republican National Convention if he stays in the race. Actually, not. As Roger Simon recalls: “When is a loser finally a loser? Ask people when it was over for John McCain in 2000, and they will tell you that it ended for McCain in South Carolina after he lost a vicious primary fight waged by George W. Bush. But that is the benefit of hindsight.Actually, McCain slogged on and won six primaries after South Carolina. It’s just that nobody cared. Once you look like a loser, you become one, and the collection of delegates here and there no longer matters.” Once there is winner with a majority of delegates it won’t even be necessary to give Gingrich a prime-time speaking slot. (Standing up to Gingrich and sending him home in a huff might do wonders for the winner’s reputation with moderate voters who can’t abide by the former speaker of the House.)

Then there is the CW notion that Mitt Romney is so reviled he can’t pull the party together and will have to lurch to the right to get the approval of Romney haters. But guess what? The Romney haters on the right are more plentiful in the blogs than in the electorate. National polls have consistently shown that Romney’s disapproval and “wouldn’t support him in the general election” numbers are lower than those of other candidates.

Finally, both the center-left chattering class and the right-wing blogosphere suggest that the GOP race is more bitter and more divisive than past races. Again, that’s simply not so. Ronald Reagan and George H.W. Bush (“voodoo economics”)? George W. Bush and Sen. John McCain (R-Ariz.)? Barack Obama and Hillary Clinton? All of these were contentious contests, sometimes downright nasty. But the eventual winner was able to put that behind him and go on to victory. In 2012, it may be even easier for the eventual nominee, since Gingrich’s reputation and following diminish day by day.

Unfortunately, like weathermen, political pundits seem never to be held to account for their erroneous predictions. And in the blog and Twitter era, the capacity for nonsensical group think ( remember when Romney’s $10,000 bet was the death knell of his campaign?) is immense. You sort of wish pundits had to list their batting average, huh? It might put their newest CW in proper context.