Senate Democratic leaders are hopeful that a compromise on the Medicare bill headed for a vote Thursday afternoon will attract some Republican support, but it probably won’t be enough to move the legislation to debate.

Majority Leader Harry Reid (D-Nev.) has indicated that some Republicans are likely to support a Medicare reimbursements substitute written by Finance Chairman Max Baucus (D-Mont.), bringing the number of Senators advocating it to the “mid-50s” —still short of the 60 votes needed to advance debate.

Majority Whip Dick Durbin (D-Ill.) said that some moderate Republicans and those in tight election races might jump ship to support Baucus’ proposal.

“It’s kind of like Red Rover. They send over Republicans that are up for re-election and worried, but there’s never quite enough. There’s a little tease, but you hope you reach a tipping point where they come around,” Durbin said, referring to a children’s game that plays on weaker team members.

Baucus settled on compromise legislation in the hopes of gaining GOP support that would delay the competitive-bidding program for medical equipment for 18 months. Some have criticized the bidding program as an unfair plan that benefits few.

However, some lawmakers say that the Medicare proposal faces an uphill battle and that getting cloture is unlikely.

Sen. Orrin Hatch (R-Utah), a Finance Committee member, pointed to a Baucus offset to pay for the Medicare Advantage program as a non-starter because it would draw a presidential veto and force negotiations to start again.

“We do not want to send a Medicare bill to the White House that is going to be vetoed and therefore put the physicians’ Medicare payments in jeopardy. It is another reason to vote against cloture: so we don’t go through that charade that we’ll have to go through if we don’t,” Hatch said.

Moreover, Minority Whip Jon Kyl (R-Ariz) said that he would recommend his Republican colleagues oppose the bill because it is too partisan. He faulted the failed negotiations between Finance ranking member Chuck Grassley (R-Iowa) and Baucus for a likely unsuccessful cloture vote.