The debate over Santorum’s electability in the fall has surprisingly skirted around some of the clearest evidence that he would lose and probably lose badly. A review of the breakdown of Santorum’s 2006 loss gives us some idea why he would be a poor general election candidate. For example, his 2006 re-election campaign saw independents fleeing from Santorum at a much higher rate than they fled the GOP nationally:

But here’s the key number: While he won independents 57 percent to 43 percent in his 2000 reelection campaign, he lost them 71 percent to 28 percent in 2006 — a pretty stunning 29-point dropoff.

Going back through the CNN exit poll for the Pennsylvania Senate race, I found a few more numbers that cast doubt on Santorum’s competitiveness in a general election. He lost moderates by 30 points (65-35), Catholics by 18 points (59-41), suburban voters by 14, and college educated voters by 22 (61-39). Even granting that he was the incumbent in a very anti-Republican election, these are not the numbers of a general election winner.