DURHAM, N.H. (AP) – Actor Michael J. Fox said Tuesday he believes both presidential candidates back expanded funding for embryonic stem cell research, but with Democrat Barack Obama “there’s no mystery about it.”

Fox, who has been a vocal supporter of stem cell research since being diagnosed with Parkinson’s disease a decade ago, was in New Hampshire to back former Gov. Jeanne Shaheen’s Senate campaign. Shaheen, a Democrat, is in a tight rematch with Republican Sen. John Sununu, who opposes increased federal funding for the research.

Though both Obama and Republican Sen. John McCain have voted to relax federal funding restrictions on embryonic stem cell research, some advocates are concerned that McCain might backtrack.

In an interview with The Associated Press, Fox said the platform plank is troublesome, but he isn’t ready to conclude that McCain has changed his mind.

“Historically, Sen. McCain has been a friend to the cause and a supporter of stem cell research. He hasn’t specifically reversed himself on that,” he said.

“Although, with Sen. Obama, there’s no mystery about it,” he added. “There’s no veil over any part of his support. His support is total and enthusiastic.”

The Republican Party platform includes opposing even private funding for research on surplus embryos, which is currently allowed. McCain’s running mate, Alaska Gov. Sarah Palin, has opposed the use of embryos in research.

Fox said he is not particularly concerned with Palin’s opposition.

“I’m not a political scientist, but my attention is at the top of the ticket,” he said.

Both McCain and Obama voted in 2006 and 2007 for bills that would increase federal funding for the research, but President Bush vetoed those plans. A campaign spokeswoman said Monday that McCain’s position hasn’t changed, but declined to say specifically what McCain would do if elected. Obama has promised to loosen the restrictions and double National Institutes of Health Funding over 10 years.

Sununu, meanwhile, voted against both bills. He has said he supports funding for research on adult and amniotic stem cells and expanding available embryonic stem cell lines using techniques that do not require the destruction of embryos.

“As the only engineer in the U.S. Senate, I’ve been proud to protect funding for the National Science Foundation from political manipulation and fully support funding for adult and amniotic stem cell research which has already resulted in a number of treatments that have proven to be successful in patient trials,” Sununu said in a statement Tuesday.

In 2007, Democrats portrayed him as the single vote standing in the way of overriding President Bush’s veto of the expansion bill.

Shaheen’s oldest daughter, Stefany, introduced Fox at the University of New Hampshire, by describing her 10-year-old daughter’s diagnosis with juvenile diabetes.

“I can tell you there is nothing more personal than having the man who stole the election from your mother in 2002 be the one vote you needed and the person standing in the way of a cure for your daughter’s chronic disease,” she said.

Scientists lately have created the equivalent of embryonic stem cells from ordinary skin cells, a breakthrough that could someday produce new treatments for disease without the moral question of embryo cloning. But Fox said it doesn’t make sense to eliminate exploration in one area because of success in another.

“Saying ‘Let’s avoid the controversy,’ or ‘Let’s go with Curtain A because we’re not quite sure what’s behind Curtain B’ I think does the country a disservice,” he said. “It’s certainly a disservice to families and patients and people who could be affected by this research.”

The star of TV’s “Family Ties” and the “Back to the Future” films was diagnosed with Parkinson’s disease in 1991 and revealed his condition publicly in 1998. Symptoms of the disease – a chronic, progressive disorder of the central nervous system – can include muscle rigidity, tremors and slowness of movement.

Fox has acted sporadically since quitting acting full time in 2000, and will appear in four episodes of FX’s “Rescue Me” this spring, playing the new boyfriend of star Denis Leary’s ex-wife.

“We hate each other instantly and it becomes combative and ugly,” he said of his and Leary’s characters. “What’s interesting about it is my character is in a wheelchair so Dennis struggles with wanting to kick my ass and what does that say about him.”

Fox said such appearances aren’t a direct attempt to further his cause.

“I don’t act that often,so when I do, my primary concern is that it be fun and something I can do,” he said. “But I think by virtue of who I am, I am attracted to subjects and situations and material that’s semi-topical and compelling, that make you think as well as laugh.”

Fox campaigned with Democrat John Kerry in 2004 and with several U.S. Senate candidates in 2006. An ad for Missouri Democrat Claire McCaskill attracted wide attention when conservative talk-show host Rush Limbaugh accused him of either acting or going off his medication.

Fox said he isn’t looking to replicate that effort in this cycle but has put the word out that he is interested in helping candidates. Shaheen, whom he met in 2004 when she worked for Kerry, was the first to respond.

In his three-minute speech to students, Fox said it’s time to let scientists be innovative in tackling a variety of diseases, without political barriers.

“Those families are counting on a new direction in Washington. They are counting on Jeanne Shaheen,” he said. “Let’s take the politics out of science. Send Jeanne Shaheen to the U.S. Senate.”

Though Shaheen led early in the campaign, the race has tightened, and a poll conducted by the University of New Hampshire for WMUR-TV released Tuesday showed her about even with Sununu.