LONDONDERRY - Steve Walter is just a regular dad who wants what's best for his son, Alex.

But Alex, 11, isn't just a regular kid. He was diagnosed with Type 1 diabetes more than six years ago. Since then, he's endured about 25,000 finger pricks and 8,000 shots. He'll continue testing his blood sugar and injecting himself with insulin for the rest of his life, unless a cure for diabetes is discovered.

So, Walter is doing what he can to get a president elected who will federally fund stem cell research at the National Institutes of Health, he said. His story, in his voice, can be heard on the radio airwaves starting today in an endorsement ad for presidential contender Sen. Hillary Clinton, D-N.Y.

"I'm a Republican, so it's kind of a unique situation," said Walter, who lives in Londonderry. "But I vote on this issue. You do anything you can to help your kid."

Walter was asked by Clinton's campaign in June to speak at an event at Dartmouth College, focused on ending Bush's war on science, Clinton campaign spokeswoman Kathleen Strand said. He spontaneously endorsed Clinton during his speech that day, Strand said.

It was just last week when Walter was contacted again and asked to share his story on the radio.

In the ad, Walter said, he takes his story right down to a personal level.

"In order for Alex to survive, we have to prick his finger 10 (to) 12 times a day," he said.

As parents, they do what they can to make sure their fifth-grader can play soccer and lacrosse, and have a chance to live to see 80.

Walter and his wife, Cathy, haven't slept a full night since Alex was 4 years old because they check his blood sugar at 11 p.m., 2 a.m. and 4 a.m. each night. He said whenever he speaks publicly for a candidate, there are a handful of parents in the audience who relate to his story and thank him.

Walter crosses party lines to help campaign for stem cell research because he said the Republicans try to turn it into a religious issue and it's not.

"It's about helping a kid like Alex," he said. "And there's also 100 million people out there who could benefit from the research."

Clinton has different values from the other candidates and more compassion, Walter said. He thinks it's because she is a mother.

And he hopes that people can relate to Clinton and relate to his story when they hear it.