President Barack Obama’s furious push for the Senate to ratify the New Strategic Arms Reduction Treaty with Russia by month’s end remains jeopardized by Republican opposition and a crowded legislative calendar.

Senate Republicans are suggesting that addressing START in December is possible, but only if Democrats shelve their long list of legislative priorities for the lame-duck session. Republicans want the Democrats to move quickly to approve funding to keep the federal government operating into 2011 and to join the GOP in supporting an extension of the Bush-era tax cuts for all income tax brackets.

Senate Majority Leader Harry Reid said Thursday that he remains committed to bringing up the Democrats’ full slate of legislation planned for the lame duck. But even if the Nevada Democrat relents, Senate Minority Whip Jon Kyl, the lead GOP negotiator on START, said Republicans and the Obama administration remain at odds over key portions of the treaty and related policy issues — and that those differences are unlikely to be resolved this month.

During a brief interview late Thursday afternoon, the Arizona Republican expressed the Republicans’ viewpoint on dealing with START before Christmas.

“It depends on Harry Reid and the Democrats in the House and in the Senate. If they choose to pursue the entire agenda that Harry Reid initially announced, it would be impossible to do everything,” Kyl said. “If, on the other hand, they cut back on key pieces of that, and if the House acts on a continuing resolution more quickly than they’ve indicated they’re going to, and we could do it more quickly — and we could start the START treaty in time to get it done — then obviously, it could get done.”

Among Kyl’s concerns with START are its implications for U.S. missile defense capabilities and whether the administration is committed to adequately funding the modernization of current nuclear weapons stockpiles.

Reid and Senate Foreign Relations Chairman John Kerry countered with a more optimistic view of START’s chances of being ratified during the lame duck.

“If we set our mind to it, we can get it done,” Reid told reporters during a Thursday afternoon news conference, following a lengthy closed-door Democratic caucus meeting.
Reid was similarly optimistic that the Senate would move on additional Democratic priorities, including a repeal of “don’t ask, don’t tell,” which bars gays from serving openly in the military, and the DREAM Act immigration measure.

Kerry described the negotiations with Kyl as “very constructive,” and said an agreement “absolutely, no question about it,” could be reached in time for START to be ratified during the lame duck.

“We’ve made a lot of progress,” the Massachusetts Democrat said. “We have some loose ends we’re trying to tie up — we’re working on. But I feel cautiously optimistic that we can get somewhere.”

Kyl, who in 1999 succeeded at sinking the ratification of an arms treaty signed by President Bill Clinton, appeared cool to that view, saying of Kerry’s assertion: “He has always thought that.”

Some Republicans have backed the treaty. Senate Foreign Relations ranking member Dick Lugar (Ind.) is one, with Sen. Bob Corker (Tenn.), who sits on the committee, saying Thursday that negotiations to resolve differences with the White House are headed in a positive direction.

But Kyl’s position on START is not Obama’s only problem.

Several Republicans on Thursday offered fresh opposition to ratifying the START during the lame duck, including Sen. Jim DeMint.

The South Carolina Republican and Sen. John Ensign (Nev.) sent a letter to Minority Leader Mitch McConnell (Ky.) Thursday, signed by 20 of their GOP colleagues, urging that START be pushed to next year, when the Republican Conference will grow from 42 to 47. Signatories to the letter include Senate Republican Policy Committee Chairman John Thune (S.D.); Conference Vice Chairman John Barrasso (Wyo.); National Republican Senatorial Committee Chairman John Cornyn (Texas); and Sen. Tom Coburn (Okla.).

Rep. Roy Blunt (R), who will be sworn in next month as Missouri’s junior Senator, previously sent a letter to Reid in November signed by 10 Republican Senators-elect asking that a vote on START be delayed to allow the Senate’s incoming freshmen a chance to weigh in on the document. DeMint is threatening to block START, should it come up for debate, in part to ensure that Blunt and his freshman colleagues have an opportunity to vote on the treaty.

“I will use every tool available to oppose an attempt to rush the debate over the START Treaty during the lame-duck session of Congress,” DeMint wrote Thursday on National Review’s website. “The newly elected Republican Senators have signed a letter asking our leadership to postpone debate on START until they take office in a few weeks and have ample time to review the details.”

DeMint, who serves on Foreign Relations, expressed concerns with the treaty, both in his online post and in the letter he and Ensign sent to McConnell. The START legislation is privileged and therefore debate on the measure cannot be filibustered, but 67 votes are required for ratification, more than are needed to overcome a filibuster.

Kyl said the issue of allowing the new crop of incoming GOP Senators to vote on START was also factoring into his calculations regarding how to proceed on the treaty.

Sen. Orrin Hatch said Republicans would be more inclined to proceed to a debate on START if Democrats put their list of lame-duck priorities on hold and focus on extending tax cuts and passing legislation necessary to keep the government funded and operating.

The Utah Republican signed the DeMint-Ensign letter, saying in a brief interview Thursday that moving to ratify START during the lame duck was problematic.

“Morally, how can they bring that up when there’s been a sea change, and you’ve got a lot of people who’ve been elected,” he said. “I don’t think it would be right.”