Three dozen moderate Democrats are warning Speaker Nancy Pelosi (D-Calif.) and Majority Leader Steny Hoyer (D-Md.) that they must show that their health care bill will cut long-term costs or they will vote it down.CBO Director Douglas Elmendorf has already indicated that the bill being considered by the House does nothing to rein in the cost of health care, and therefore may not be sustainable outside the ten-year budget window, the Members say in the letter. We will be unable to support any health care legislation that doesnt meet the presidents goals of driving down and holding down the cost of health care, as determined by CBO.The letters signers noted that the Congressional Budget Office has not issued final judgment on the revised House health care bill, but they are clearly ratcheting up the pressure on Pelosi as she tries to knit together the liberal and conservative wings of her Caucus.The letter, led by Reps. John Barrow (D-Ga.) and Glenn Nye (D-Va.), praises the Senate Finance Committees bill for cutting $81 billion from the deficit over the next decade while cutting the cost trajectory for health care in future years.Pelosi vowed Thursday during her weekly press conference that the House bill must reduce the deficit in the second decade, not just the first, but she does not yet have a conclusive CBO statement to that effect. She also dismissed criticism of the original House bill, saying that it no longer exists. We feel very confident, and everything we do is to drill down on the fact that, of course, the bill has to be paid for there is no question about that but that it also has to reduce the deficit in the out-years, she said.The 36 moderate Democrats are largely, but not exclusively, Members of the fiscally conservative Blue Dog Coalition, and are just shy of the number of Democrats needed to bring down a bill on the floor.Hoyer said Thursday that he had not yet seen the letter but was aware of it, and he said he agrees that the House bill needs to bring down the cost curve beyond the next 10 years.I share that view, and were working to do that, Hoyer said.A senior Democratic aide said the CBO score will be crucial to passing the bill.If our CBO numbers dont come back showing solid deficit reduction and a holding down of long-term costs, then we will not have the votes to pass the health bill and we will have to make changes, the aide said. The aide added that it would be politically stupid to pass a bill that added to the deficit and went against the president on top of it.But Nadeam Elshami, spokesman for Pelosi, said the final House bill will "cost less than $900 billion over ten years, achieve savings and tackle inefficiencies in the current health care system and reduce the deficit over the next 20 years."So far, according to Democratic aides, the CBO has been unwilling to assure the House bill would cut costs beyond the first decade. I think they are trying to make clear that leadership trying to gloss over or rationalize a weak or shaky CBO score is not going to fly, the aide said.