Against a Democratic congressman who opposed abortion, Santorum dramatically underperformed with women voters. That would likely repeat itself if he emerged as the Republican nominee against President Obama.

Santorum won an impressive 57 percent of the vote among men; that number increased to 60 percent just looking at white men. But among women, Santorum lost to Klink, winning just 48 percent of the vote. Among white women, he barely inched past the Democrat, 52 to 47 percent…

Since that election, Santorum wrote his book “It Takes A Family” and has been even more outspoken on cultural issues that galvanize the GOP base and some culturally conservative independents, but have been a turnoff to many female voters. In 2006, Casey won a whopping 61 percent of the female vote, as part of his across-the-board win.