http://www.gallup.com/poll/152240/Romney-Ties-Obama-Swing-States-Gingrich-Trails.aspx
That is an important point.
To win this November, we have to energize our base voters, deal with the reality that President Barack Obama’s race brings in a significant number of voters who don't typically vote, and bring a number of swing states into the Republican column that often vote Democrat.
Newt Gingrich energizes some of our base but seriously antagonizes other parts. He himself admits he has baggage.
The old “Reagan Democrats” — ethnic blue-collar whites, often Roman Catholic, who are willing to vote Republican based on social issues — are key to winning many of those swing states. That's a constituency that's virtually tailor-made for Rick Santorum to pick up.
I'm not saying Gingrich can't do it, but I am saying Santorum has a history of doing so for nearly all of his political career winning races in predominantly Democratic constituencies until his last election, in which he was defeated by a pro-life Democratic son of a pro-life Democratic governor who took the same model of Mitt Romney, i.e., act like the opposite party to get elected.
Given the wild swings that have happened so far in this election cycle, I don't want to assume, with only three states having yet voted, that Santorum can't win the nomination. I readily grant that right now it looks like Gingrich is our best chance of defeating Romney, but who would have said that a few months ago?
Time will tell.