Read this:
Recently, I was attacked by one of my opponents because when I ran for Governor I promised to maintain the status quo with regards to laws relating to abortion in Massachusetts. Of course, I kept that promise. But in Massachusetts, that meant vetoing pro-choice legislation – as I consistently did as Governor.Excerpt from Governor Mitt Romney's Remarks At The National Right To Life Convention Forum, June 15, 2007
That doesn’t match what he said in the video.