There is a reality that you need to realize as well. There is a sizable portion of the conservative community (including myself) who will not vote for Romney, under any circumstances. Romney is not attractive enough to independents to make up for the loss of the Republican core. His general election campaign, IMO, is doomed to defeat. At least with McCain, we could remember the days he was fighting for Reaganism. At best, Mitt Romney was AWOL during the Reagan fights or was opposing Reaganism (if his own words from his campaign with Ted Kennedy can be believed). Lining up behind Mitt Romney is surrendering the soul of the Republican party.
Given Obama's vulnerability on the issues, the last thing we need is a "me-too" candidate like Romney. The Republican candidate to win has to emphasize the differences between himself and Obama as Gingrich or Santorium would do, not blur them like Romney would.
Four more years of Obama. The is no way independents will vote for Santorum.. Not going to happen.