Stems Cells in July

Reuters / ABCNews

Nearly a year after Senate Majority Leader Bill Frist made his surprise endorsement of a bill to allow federally backed stem cell research, he has whittled down many obstacles to Senate passage, senators and aides said on Thursday.

The Tennessee Republican, a potential presidential candidate and a physician, says research on cells derived from human embryos leftover from fertility treatments has vast potential to treat deadly diseases.

Many of his fellow anti-abortion conservatives, however, oppose the research because the embryos are destroyed. Frist has said he would like the Senate to vote as early as next month, although President George W. Bush has vowed to veto it.

Would this be the President's first veto? It's only been five years coming.

Senator Santorum has promised a vote against this bill.