They say that the definition of insanity is doing the same thing over and over again and expecting a different result. Why is it that the Republicans in Congress seem so determined to prove this maxim?

Let’s start with the Affordable Care Act, a k a Obamacare. The exchanges that are at the heart of Obamacare — making it possible for people who are currently uninsured to buy health care — open for business on Tuesday. Ever since the Republicans took control of the House, they have held vote after vote to roll back the law, even while ignoring important business like, say, fixing the Postal Service. I think it’s been 43 times in all — votes that have been utterly pointless, in that the Senate is still run by Democrats, and the law is President Obama’s signature achievement, and there’s no way on God’s green earth it will be repealed.

But never mind. As Oct. 1 has neared — the date both Obamacare kicks in and the government needs to be funded — Republicans moved to another tactic, which was every bit as hopeless. They began demanding that Obamacare be reversed — or at least delayed — as part of any deal to keep the government running. (At one point they had a lengthy wish list that was so implausible it was almost laugh-out-loud funny.)

But to the surprise of absolutely no one, when Republicans added the anti-Obamacare language to the “continuing resolution” designed to finance the government (for all of six weeks!), the Senate quickly rejected the House bill and insisted instead on a continuing resolution that did nothing but what it was supposed to do: fund the government. Republicans, meanwhile, would not back away from their demand that the “C.R.” had to be linked to a delay in Obamacare.