Congress voted to give scientists broader access to embryonic stem cell lines for federally funded research. But Bush vetoed the legislation in July, and the House fell 51 votes short of the number necessary to override it.

Fox would like to elect enough lawmakers who favor the research to pass another expansion and override a presidential veto.

"The veto was not a surprise, but it still stung," Fox said in an interview. "In the entire community of people with disease and chronic illness and spinal cord injury that deal with stem cell research, we want our voices heard and we want to be in a position next year to have a veto-proof margin so we can move ahead with this."

Still, many Republicans point out that most voters are more concerned about the war in Iraq and other issues than they are about stem cell research as they evaluate the two Missouri Senate candidates.

In Columbia the other day, Talent addressed the party faithful at Boone County Republican headquarters during a long day of campaigning with the state's senior senator, Kit Bond, R-Mo. He touted his efforts to reach across the aisle and work with Democrats to tackle the problem of methamphetamine addiction, to pursue energy independence with increased ethanol production and drilling in the Gulf and the Arctic, as well as the need to secure the nation against terrorism.

"If there's an international phone call and al-Qaida is on the line, we ought to find out what they're talking about," Talent told the supportive audience.

One thing Talent did not address was his opposition to embryonic stem cell research or the ballot initiative. In an interview, he said most people don't vote based on just one issue, but rather consider the candidate as a whole.

"There's a range of issues people are concerned about — the war, energy prices — health care comes up quite a lot, believe it or not, because that's something people are struggling with on a day to day basis," he said.

Still, for those who are interested, Talent's aides carry a copy of a nine-page speech he delivered on the Senate floor in February 2005 in which he expressed his concerns about cloning and noted that the rewards from creating a pluripotent stem cell are purely speculative.

Meanwhile, he's sticking to what he wants to talk about, while McCaskill sticks to her issues.

"Ballot issues are something you really can't do anything about," Talent said. "So I try to focus my campaign on what I can do something about, it just makes sense to me."

McCaskill said she believes that in a low-turnout, non-presidential year, the people who feel most strongly about an issue will go to the polls and vote. And she argues that the intensity belongs to the people who want to protect and expand embryonic stem cell research.

"If you feel really intensely in favor of this, that means you are informed, you're knowledgeable and you know that there are two Senate candidates — one who is really good on this issue and one who is really bad on this issue," she said.