THE GOP’S FLEETING LOVE FOR THE CBO…. Back in January, the Congressional Budget Office issued a preliminary assessment of the administration’s stimulus package. It was only a partial look at an out-of-date proposal, but it bolstered Republicans’ criticism, so the GOP ran with the misleading numbers. Soon after, a more complete CBO report was issued, it bolstered the Democrats’ case, and all of a sudden, Republicans’ love and respect for the CBO disappeared.

We’re seeing the exact same scenario play out again.

Last week, the Congressional Budget Office scored an incomplete Democratic health care proposal, issuing an unhelpful analysis with little practical value. House Minority Whip Eric Cantor (R-Va.) not only accepted the CBO numbers as gospel, but called the analysis “the turning point in the healthcare debate.”

This week, the CBO ran the numbers on the Democratic cap-and-trade, and in the process, discredited the Republican talking points on the proposal. Cantor’s fickle love for the CBO, predictably, faded quickly.

“Today, now we are reading the reports that have come out this week that CBO has now reduced its cost estimate to say that it is only $160 that families will be impacted by the cap and trade bill. I think that now CBO has now entered the realm of losing its credibility.”

Um, congressman? If you believe the CBO when it tells you what you want to hear, and reject it when it delivers bad news, it’s not the Congressional Budget Office that’s “losing credibility.”

In January, the New York TimesDavid Brooks wrote that President Obama is “going to have to prove the hard way that he meant what he said about being pragmatic and evidence-based. That means he won’t sweep a C.B.O. study under the rug simply because the findings are inconvenient.”

It’s tempting to think, under the circumstances, that the criticism might now be directed at congressional Republicans, except no one has ever accused them of being pragmatic and evidence-based.

Our ideas can save democracy... But we need your help! Donate Now!

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.