Vice-presidential hopeful John Edwards has sparked a row by claiming that under a John Kerry administration “people like Christopher Reeve will get up out of that wheelchair and walk again”.
Mr Edwards raised eyebrows with the pledge at an election campaign rally, a day after the death of the paralysed Superman actor was announced.
The Kerry team has repeatedly promised that it would allow stem cell research if in power, opening the way for potential cures for diseases.
By contrast President George Bush has placed strict limitations on the use of the controversial science, which often uses human embryos.
Speaking in Iowa, Senator Edwards said Reeve, who died on Sunday, “was a powerful voice for the need to do stem cell research and change the lives of people like him”.
He said: “If we do the work that we can do in this country, the work that we will do when John Kerry is president, people like Christopher Reeve will get up out of that wheelchair and walk again.”
The North Carolina Democrat’s comments sparked an angry response from Senate Majority Leader Bill Frist, a Republican.
Mr Frist, a heart surgeon from Tennessee, called the remarks “crass” and “shameful”.
“I find it opportunistic to use the death of someone like Christopher Reeve - I think it is shameful – in order to mislead the American people,” he said.
He said: “We should be offering people hope, but neither physicians, scientists, public servants or trial lawyers like John Edwards should be offering hype.
“It is cruel to people who have disabilities and chronic diseases, and, on top of that, it’s dishonest.
“It’s giving false hope to people, and I can tell you as a physician who’s treated scores of thousands of patients that you don’t give them false hope.”
Edwards’ campaign spokesman Mark Kornblau replied that under Mr Bush such breakthroughs may never be possible if science is hindered.
“What’s crass is George Bush standing in the way of promising stem cell research,” he said.
Under the Bush Administration, embryonic stem cell research is strictly limited to cells already in existence.
But the science could one day help find cures for Parkinson’s disease, juvenile diabetes and Alzheimer’s disease.
Reeve, who was paralysed in a horse riding accident nine years ago, had been central in the campaign to increase funding stem cell research.
Just days before his death, Reeve was mentioned by name by Massachusetts Senator Mr Kerry during a debate with the President in Missouri.