IDIOCY WATCH…. As things stand in the Senate, members will vote on repealing “Don’t Ask, Don’t Tell” on Sunday, and consider New START ratification next week.

But Sen. Bob Corker (R) of Tennessee has a different idea. Indeed, today he argued on the Senate floor that if members pursue DADT repeal, Republicans may very well deliberately undermine American foreign policy by killing the nuclear arms treaty.

As Corker sees it, DADT repeal is “absolutely partisan,” and is advancing to “accommodate activist groups.” That’s ridiculous and he knows it. The Pentagon specifically urged the Senate to approve repeal during this lame-duck session, as has the chairman of the Joint Chiefs. The repeal push enjoys bipartisan support, and has the backing of the vast majority of the public.

Corker disagrees? Fine. He can vote against it. He can even filibuster it. But today he suggested even considering DADT repeal may cause Republicans to kill arms control out of spite.

“I’m hoping that those [issues like DADT repeal] will be taken down or else I don’t think the future of the START treaty over the next several days is going to be successful, based on what I’m watching.”

That’s genuinely insane. Military and diplomatic leaders have explicitly made the case that New START is vital to American foreign policy and national security. Bob Corker, who already voted for the treaty at the committee level, is prepared to watch the treaty die … because he doesn’t like gay people? Because the Senate might honor a direct request from the Pentagon about expanding military service qualifications?

I should also note that Sen. John McCain (R-Ariz.) was also on the floor today, addressing New START. After seemingly endorsing the treaty last week, and voting with Democrats on the motion to proceed this week, McCain offered a sputtering, incoherent tirade today condemning New START. I’d like to note why he’s opposed, but after listening to McCain ramble, I haven’t the foggiest idea what he’s even thinking.

Watching the Senate has been pretty painful lately, but listening to Republican senators’ arguments against New START today has, in all seriousness, brought a new round of shame to the once-great institution.

Update: Corker elaborated on this soon after. Here’s the rest of the story.

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.