These deeply gratifying developments hardly spell the end of partisanship, which is likely to return with a vengeance in the next Congress. But they do suggest that many Republicans are willing to reject Mr. McConnell’s particularly noxious version, under which any bill, no matter how beneficial for the country, can be blown up if it could be seen as a victory for President Obama. On Tuesday, to pick one shabby example, he made a thoroughly underhanded attempt to sabotage the repeal of “don’t ask, don’t tell” when he thought no one was looking.

In a more rational world, of course, the ratification of New Start could have been done by unanimous consent. Though the treaty is vital, it makes relatively modest reductions in the nuclear stockpile and continues the inspection regime employed by Democratic and Republican presidents going back to Ronald Reagan. If the same document had been signed by a Republican president, it would have been approved months ago.

In the obstructionist climate of the 111th Congress, the ratification could be done only in the last hours. Mr. McConnell and his allies, notably Jon Kyl of Arizona, put up a series of specious arguments to delay it, mostly centering around a fiction: that the treaty would prevent the United States from erecting a missile defense system. Their efforts backfired, making Mr. Obama’s victory ring more loudly that it should have.

Thirteen Republicans wouldn’t buy that nonsense, and others saw the wisdom in letting all Americans serve their country honestly and openly. Those defeats and others infuriated the party’s dead-enders. “Harry Reid has eaten our lunch,” complained Senator Lindsey Graham of South Carolina, who voted against both measures, referring to the majority leader.

There were disappointments in the lame-duck session, and Mr. Obama said at a news conference that the biggest was probably the Republicans’ killing of the Dream Act, which would have given the children of illegal immigrants a chance at being legal if they serve in the military or attend college. The failure of the Senate to pass a spending bill for the current fiscal year means that the budget fights in the next term will be deeper and longer, and potentially more destructive to the economy.