Scott Brown didn’t run as a pro-life candidate, but like Mitt Romney in 2002 he positioned himself to the right of his Democratic opponent on abortion in order to win pro-life votes. (In Romney’s case, this positioning helped him pivot to an actual pro-life position when he decided to run for president.) Brown specifically opposed federal funding of abortion.
Now, Brown is not alone in saying he opposes federal moneys for abortion while supporting federal funding for Planned Parenthood. There are others who have argued that funding the country’s leading abortion provider and one of its leading advocacy groups on behalf of legal abortion is distinct from funding abortion itself. (Given the fungibility of the money, even that limited point is debatable.) There are even self-described pro-lifers who argue that Planned Parenthood’s support for contraception reduces abortions.
But Brown didn’t run as a full-blown Bill Weld/Rudy Giuliani social liberal during his Senate campaign, nor did he vote like one in the Massachusetts legislature. He’s always been a splitter on social issues, trying to give social liberals few reasons to fear him and social conservatives a few reasons to vote for him. With his Planned Parenthood stance, he has given social liberals one less reason to fear him and social conservatives one less reason to vote for him.