I’ll answer you this way: as a result of signing taxpayer-funded abortion into law, Romney has blood on his hands. God’s view of homosexuality is clear, but Romney cuddled up to sodomites every chance he got.
So, I personally cannot understand how anyone with principles could endorse the man.
Not everybody evaluates politicians based on just one criterium. Many evaluate based on multiple criteria and are are willing to accept them based on agreement on a sufficient majority of issues even they disagree on some important issues, even if they disagree on their most important idea. This may or not be right, but it would be unrealistic to deny it is common. That it is a reality one must learn to deal with it, at least until humanity is perfected. And I don't expect to live to see that day.
Santorum is on the record as being willing to work with those with whom he disagrees if he believes it will advance the big picture. He explains his Spector support as based on his (Rick's) pro life stance and in spite of Spector's pro-abort stance. He got Spector to promise, in his role as head of the Judiciary committee, to promise to let pro-live Bush Supreme court picks through for a Senate vote. Spector could have blocked them, but let Roberts and Alito through, keeping that promise. Earlier Spector had his greatest moment defending Clarence Thomas. The liberal, pro-choice, Spector deserves significant credit for 3 pro-life votes on the Court. Pat Toomey, to whom IIRC I sent $ that race, would have had a harder timing winning PA that year than in his win in the good GOP hear of 2010. Had a Rat beat him they might have held the Senate and forced more "Kennedy" types on Bush. And even Pat Toomey has forgiven Rick for supporting Spector.
Are Roberts and Alito worth the heartburn Spector produced at other times? It's hard to say, but Santorum's pick there is not indefensible. His last minute endorsement of Romney in '04 was the product of similar reasoning. As polls of Freepers at the time showed the majority of us (doubtless many after heavy doses of antacids) then supported Romney over Huck and McCain, Santorum's reason wasn't uncommon. Happily, at this time, there are still multiple options better than Mitt. If it ever gets down to Mitt vs. Wrong Paul vs. Obama, Freepers won't be suffering heartburn over their choice, they'll be suffering angina.