The bill was passed by 63-37 votes, four short of the two-thirds majority that would be needed to override the presidential veto. President Bush left little doubt that he would veto the bill, his first in nearly six years as president, despite late appeals on its behalf from fellow Republicans Nancy Reagan and Governor Arnold Schwarzenegger.
"The simple answer is he thinks murder's wrong," said Tony Snow, the White House spokesman. "The president is not going to get on the slippery slope of taking something living and making it dead for the purposes of scientific research."
Senate supporters of the bill likened that logic to opposition suffered by Galileo, Christopher Columbus and others who were rebuked in their time but vindicated later.
Polls show as much as 70 per cent public support embryonic stem cell research.
"There has been an upsurge of demand," said Senator Hillary Clinton. Support for the legislation "has crossed every line we could imagine, certainly partisan lines, ethnic, racial, geographic lines."
Two other bills
The Senate also passed two related measures - 100-0 in each case - that Bush was expected to sign into law.
The Senate also passed two related
measures Bush is expected to sign
One would encourage stem cell research using cells from sources other than embryos in an effort to cure diseases and treat injuries. The other would ban "foetal farming," the possibility of growing and aborting foetuses for research.
Those two bills were headed for a House vote later on Tuesday. Bush was expected to sign them when he vetoes the embryonic stem cell research bill, as early as Wednesday.
Nineteen Republicans voted for the bill, while one Democrat, Senator. Ben Nelson voted against it.
Snow said the president had issued 141 veto threats during his five and a half years in the White House, often against spending increases for domestic programmes. "This was the first time no deal could be cut," Snow said.
Appeal to BUsh
Schwarzenegger, the California chief executive and movie star, wrote to Bush, "Mr. President, I urge you not to make the first veto of your presidency one that turns America backwards on the path of scientific progress and limits the promise of medical miracles for generations to come."
Mrs. Reagan, meanwhile, had quietly made calls to a few senators to try to build support toward a veto-proof margin in the Senate; but no one was predicting one.
The White House and Bill Frist, the Senate Majority Leader, worked for what they considered the next closest thing: Stem cell-related bills Bush could sign.
"Mr. President, I urge you not to make the first veto of your presidency one that turns America backwards on the path of scientific progress and limits the promise of medical miracles for generations to come"
Enactment of the bill to encourage research on adult stem cells enables Bush and other opponents of embryonic stem cell studies to say they, nonetheless, support stem cell science.
''The president is not opposed to stem cell research, he's all for it,'' Snow said.
Embryonic stem cells are essentially master cells, able to morph into all the cell types found in the body. If scientists could learn to control these cells and coax them into becoming specific types on demand, they could grow replacements for damaged tissue. The idea is to use this process - still theoretical - to cure or treat a raft of diseases and injuries, from diabetes to Alzheimer's and spinal cord damage.
Opponents of federal funding for embryonic stem cell research say studies on cells derived from adults and umbilical cords is more advanced, less controversial and more deserving of federal funding.
How fast the science for both types of stem cell research proceeds depends on how much money the federal government is willing to spend, and for which kind. Supporters of the embryonic stem cell bill say the engine of public funding would greatly accelerate cures and treatments.
The House last year fell 50 votes short of a veto-proof margin when it passed the same embryonic stem cell bill, 238-194. Fifty Republicans voted for the bill, in defiance of Bush and many of their party leaders.