This is just a tiny, minuscule sample of volumes worth of info, look for the rest and more current stuff on other threads when the topic comes up.
http://www.youtube.com/watch?v=a9IJUkYUbvI
However, as governor of Massachusetts, Romney did take a principled stance against tax payer funding of Harvard's embryonic stem cell institute. It was a politically risky move and took a lot of courage. Harvard is very powerful in Massachusetts. It's one of the state's largest employers.
But Mitt's flip-flopping in this debate was terrible. I think he would have garnered more respect even from the ultra-liberals in MA if he took a principled position instead of a pandering one.