Senate Democrats are putting off consideration of the defense authorization bill until after the summer recess in hopes that Sen. John McCain will be a more agreeable negotiator after his August primary.

The move reflects a hurdle that Democrats have faced across multiple issues this year: From immigration to campaign finance reform and now the annual bill that sets policy for the Pentagon, Senators and aides maintain they have lost a key GOP ally who has tacked hard right to win his party’s nomination on Aug. 24 against conservative former Rep. J.D. Hayworth.

“There is a hope that things can return to an equilibrium with Sen. McCain to act on things that need to be done this Congress,” one Democratic aide said. “It would be a pleasant surprise if he does.”

Republicans, however, maintain that McCain’s opposition to components of the defense authorization — particularly language repealing the “don’t ask, don’t tell” policy — will not fade after August.

The Arizona Republican, who is ranking member of the Armed Services panel, voted against the measure in committee in May despite successfully inserting language to send 6,000 additional National Guard troops to the Arizona border.

McCain has maintained that a defense bill is not the appropriate vehicle to push a DADT repeal, an argument he made last year when Democrats added an amendment on hate crimes to the Pentagon measure. McCain ultimately voted for the defense authorization last year and tempered his remarks, and Democrats are banking on him doing the same this time.

Democratic leaders are looking for a legislative win in repealing DADT, a policy enacted under the Clinton administration that bans openly gay service members from the military. The majority particularly wants to push the repeal before a Pentagon review of the policy is released in December, and with the support of Sen. Susan Collins (R-Maine), Democrats believe they have the votes to fend off a GOP-led filibuster.

Democrats rallied interest groups leading up to the Armed Services Committee’s markup in May and then quieted down to avoid stirring up critics. The September timing for the defense measure, later than most years, appears part of that strategy as Members look to make good on one of President Barack Obama’s election promises.

“I always resist questioning peoples’ motivation. I do know this is a tough election year, and I do know there are questions in conservative circles,” said Sen. Mark Udall (D-Colo.), who sits on the Armed Services panel.

[IMGCAP(1)]Sen. Joe Lieberman (ID-Conn.), a McCain ally who campaigned for the Republican during the 2008 president election and is the author of the DADT amendment, said the political posturing around DADT and other issues was “unfortunate.”

“It’s just part of a general distemper that has affected our work here,” Lieberman said. “I’m afraid we’ve settled into pre-election mode, which is not good for the country.”

Republicans reject the notion that McCain has altered his modus operandi in the runup to his primary. They note that he has been agreeable with Democrats on some fronts, such as dropping his hold Tuesday of James Clapper’s nomination to be director of national intelligence, and they toss aside suggestions that he will return in September with fresh views on any front.

“He’s not going to change his mind, if that’s the idea,” fellow Arizona Republican and Minority Whip Jon Kyl said. “If they’re waiting for Sen. McCain to change his mind or take a different position, they’ll be waiting a long time.”

Indeed, McCain appears to be charting his own path on the controversial question of revisiting the 14th Amendment to the Constitution, which grants citizenship to the children born to illegal immigrants living in the United States, as some conservatives are demanding.

“I believe that the Constitution is a strong, complete and carefully crafted document that has successfully governed our nation for centuries and any proposal to amend the Constitution should receive extensive and thoughtful consideration,” McCain said in a release. “Immediate and full implementation of the McCain-Kyl 10-Point Border Security plan will assist in addressing concerns associated with this issue.”

Defense and immigration are just two of the red-meat issues McCain has loaded onto his plate going into the final stretch before the primary. The 2008 presidential nominee penned a USA Today editorial last month announcing he would not support Elena Kagan’s nomination to the Supreme Court. His decision largely turned on the fact that Kagan limited military recruiters’ access to the Harvard Law School campus during her tenure as dean.

“While I strongly disagree with Kagan, I take no issue in terms of her nomination with her opposition to President Clinton’s ‘don’t ask, don’t tell’ policy,” McCain wrote July 7. “She is free to have her own opinion. Kagan was not free, however, to ignore the Solomon Amendment’s requirement to provide military recruiters equal access because she and many of her colleagues opposed ‘don’t ask, don’t tell.'”