THE sweeping Democratic midterm losses last week raise serious questions for President Obama and a lame-duck Congress. Voters want government brought closer to the vision the framers outlined in the Constitution, and the first test could be the fate of the flawed New Start arms control treaty, which was signed by President Obama and President Dmitri Medvedev of Russia last spring but awaits ratification. The Senate should heed the will of the voters and either reject the treaty or amend it so that it doesn’t weaken our national defense.

The treaty’s supporters are likely to try to rush it through the Senate before Congress adjourns. They worry that since the Republicans have gained six seats, New Start will fail to get the required two-thirds majority when the new Senate convenes in January.

Senators should be in no hurry. The Obama administration’s main strategy in this two-minute drill is likely to emphasize a “resolution of ratification” that the Foreign Relations Committee approved along with the treaty in September. But that resolution, which supposedly addresses concerns about missile defense and modernization of the nuclear arsenal, is a Trojan horse. Any senators who fall for this ploy will not only imperil our safety, they will also undermine the Senate’s formidable powers in the treaty-making process.

New Start’s faults are legion. The low limits it would place on nuclear warheads ignore the enormous disparities between American and Russian global responsibilities and the importance of America’s “nuclear umbrella” in maintaining international security. The treaty’s constraints on launching platforms would impede Washington’s ability to use conventional warheads even in conflicts far from any Russian interest or responsibility. There are plenty of other deficiencies, from inadequate verification provisions to leaving Moscow’s extensive tactical nuclear weapons capabilities unlimited.