‘REGARDLESS OF CONSTITUTIONALITY’…. It’s hardly a surprise that Sen. Jim DeMint (R-S.C.) has fully embraced “Tenther” attitudes — rejecting the federal government’s authority to do much of anything based on a long-discredited, right-wing interpretation of the 10th Amendment.

So, when DeMint told Aaron Wiener over the weekend that he thinks Congress lacks the “constitutional authority” to intervene on health care policy, it was fairly predictable. Of far greater interest was DeMint’s response when asked about Medicare. This matters, of course, because if there’s even a shred of intellectual consistency to the Tenther approach, everything from Medicare to Social Security, the G.I. Bill to the interstate highway system, should be deemed unconstitutional.

DeMint expressed doubts as to the legality of Medicare under the Constitution, but said, “Regardless of constitutionality, it is a promise that we have to keep…. I think Medicare and Social Security have to be protected.”

“Regardless of constitutionality” strikes me as an instant classic. Indeed, it’s the worst of both worlds — DeMint’s ideology is so far gone that he actually believes Medicare and Social Security are unconstitutional, but DeMint’s principles are so weak that he supports the illegal programs anyway.

For the American mainstream, DeMint’s legal analysis makes him a nut. For the Tenther fringe, DeMint’s willingness to deliberately endorse policies he considers unconstitutional makes him a sell-out.

There’s also the small matter of Republicans trying to convince America’s seniors that it’s the GOP, not Democrats, who are the real champions of Medicare. That is, of course, what the RNC’s Michael Steele has been arguing for weeks.

That pitch is all the more ridiculous when, over the course of five days, Sarah Palin recommends privatizing Medicare and Jim DeMint argues Medicare’s existence is illegal.

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.