With talks between GOP House leadership and the White House over reopening government and extending the debt limit broken down, Senate Democratic and Republican leaders are now for the first time discussing a path beyond the impasse.

With the blessing of their members, Senate Majority Leader Harry Reid and Minority Leader Mitch McConnell began talking in the last 24 hours to try to work out a deal that could also pass the House.

Senate Democrats rejected a plan modeled on Senator Susan Collins' suggestion, which recently gained momentum in the Senate and included a six-month continuing resolution to fund government and a three-month debt limit extension. Her plan would also have delayed for two years the medical device tax used in part to fund Obamacare.

Rather, the contours of the debate seem to be taking shape around the length of the continuing resolution and debt limit extension, and on what Obamacare concession Republicans might extract.

Democrats chafe at a short-term debt limit extension because it would mean another fiscal fight in the heart of the holiday buying season. They also argue for a shorter CR so they can renegotiate the topline spending figures and undo sequestration, which they view as harmful.

Republicans, on the other hand, want a shorter extension so they can pivot from this crisis, which has proved politically costly to them, to discuss spending cuts, entitlement reform and tax reform. They also want a longer continuing resolution, which would lock in the sequestration cuts gained in the 2011 Budget Control Act.

Despite the disagreements, there's cautious optimism, now that Reid and McConnell are talking.

"There's such a universe of possibilities out there but we haven't quite agreed on a specific set," Assistant Majority Leader Dick Durbin, D-Ill., said.

Also on Saturday, Senate Republicans blocked Reid's debt-limit extension measure in a procedural vote, 53-45, along party lines. Reid voted against his bill for parliamentary reasons. The extension would have taken the government through the November 2014.

There was little incentive for Republican senators to vote with the majority to advance the Democratic proposal now that the leaders are discussing a path forward.

But the vote gave senators an opportunity to further their talks as members fraternized on the Senate floor. For example, McConnell and Sen. Chuck Schumer, D-N.Y., the No. 3 Senate Democrat, sat huddled together talking throughout much of the vote.

The talks between Reid, McConnell, Schumer and Sen. Lamar Alexander, R-Tenn., opened Saturday morning, with Reid describing the conversations as "extremely cordial," and preliminary.

Senators also recognized that whatever the deal is it will need to clear the House, which has been unable to offer legislation acceptable to the Senate and the White House. But some Senate Democrats also said they are fed up with House Speaker John Boehner.

"At this point, they have dealt themselves out of this process," Durbin said. "They cannot agree among themselves and that makes it extremely difficult to take them seriously."

Senate Republicans sounded optimistic Saturday that such a deal was within reach and also realized the House would have little time to act given the Oct. 17 debt limit deadline.

"Hopefully we're not wasting our time sending legislation that the House wouldn't accept," said Sen. Roy Blunt, R-Mo.