Every two years, when the Senate’s newly-elected members take office, the Constitution opens up a brief window when the Senate’s rules can be changed with just 51 votes — the rules typically require a two-thirds majority to make any changes. Last year, several senators proposed taking advantage of this window to reform the filibuster rule and prevent Senate Republicans from continuing their unprecedented campaign of obstruction of bills and nominees. Ultimately, however, these reforms failed because too many Senate Democrats were unwilling to move forward with them.

Yesterday, in a floor speech, Senate Majority Leader Harry Reid (D-NV) admitted that the reformers were correct, and that the senators who kept the filibuster intact were wrong:

If there ever were a time when Tom Udall and Jeff Merkley were prophetic, it’s tonight. These two young, fine senators said it was time we changed the rules in the Senate, and we didn’t. They were right. The rest of us were wrong — or most of us now anyway. What a shame. So here we are, wasting time because of the Republicans. … And then, to top it off, one of the finest members of the Senate we’ve had, ever, was defeated yesterday by a man, listen to this, Mr. President, who campaigned on the platform that there’s too much compromise in the Senate. And he’s going to come back here and not compromise with anybody on anything. Now that’s what we need in the Senate, more people who are willing to do nothing but fight.

Reid’s frustration with the result in the Indiana GOP Senate primary closely maps concerns that ThinkProgress raised shortly after Tea Party candidate Richard Mourdock defeated long time incumbent Sen. Richard Lugar (R-IN). In the wake of Mourdock’s success running on a platform of uncompromising obstructionism, it is unlikely that any Republican senator will be willing to cross party lines in order to pass even the most essential legislation or to fill crucial jobs such as a seat on the Supreme Court. As Reid now seems to recognize, the choice facing Senate Democrats is whether to dramatically reform the Senate rules or leave America completely unable to govern itself.

Despite their unwillingness to do so last year, however, they will have another opportunity to do so very soon — provided they have at least 51 votes in favor of reform. Next January, when the 113th Congress convenes, another window opens enabling the Senate’s rules to be changed by a simple majority vote.