Support on the Hill for drastic spending caps appeared to be gathering momentum recently. Senate Republicans embraced the idea rather enthusiastically, as did Independent Joe Lieberman and “centrist” Democrats like Claire McCaskill and Joe Manchin.

The fear has been that this truly ridiculous idea would take hold as a bipartisan consensus measure, and perhaps even become part of a deal on the debt ceiling. It’s reassuring, then, to see Democratic leaders — both ends of Pennsylvania Avenue — step up on this.

The White House and Senate Democratic leaders, worried that a proposal to cap federal spending could gain traction in Congress, have mounted a drive to discredit the idea. […]

The bill’s lead sponsor is a Republican, Sen. Bob Corker of Tennessee. But two Democratic senators have signed on, and party leaders worry that more could join—especially senators facing tough re-election challenges in swing states who are looking for ways to burnish their credentials as deficit-cutters. […]

Democratic leaders argue that while the cap may be appealing and easy to explain to voters, it sets a ceiling so low that it would force changes in Medicare and other programs as drastic as those called for by House Republicans, which Democrats have roundly rejected.

Of course, Democratic leaders don’t just argue this; Democratic leaders are right about this. It’s arithmetic — if all federal spending is limited to 20.6% of the nation’s gross domestic product, massive cuts to Medicare and Social Security would be unavoidable. Proponents of the caps don’t even try to dispute this; it’s just reality.

Given this, it’s good to hear that White House budget director Jacob Lew hosted a budget presentation for Senate Democrats yesterday, and made clear that the proposed spending caps pose real problems.

This is, of course, the same issue that has managed to get and Third Way on the same page, which rarely ever happens.

I’ll gladly concede that my coverage of this is repetitious, but I think it’s worth banging the drum anyway. Imposing these statutory spending caps on Congress, with the goal of automatically slashing public investments in practically everything, is insane.

As the Center on Budget and Policy Priorities’ Paul Van de Water explained to the Senate Finance Committee last week, “Imposing an arbitrary limit on federal spending would risk tipping faltering economies into recession, make recessions deeper, and make recovery from a recession more difficult.”

Heather McGhee also did a nice job summarizing the case against caps, calling the Corker/McCaskill plan what it is: “a depression maker.”

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.