I've always found the idea that evangelicals are staunchly anti-Catholic as a rule to be largely an invention of Catholics with a persecution complex and secularists trying to make evangelicals out to be even more bigoted then they really are, and I'd say that Rick Santorum's campaign provides quite a bit of evidence in favor. The only anti-Catholic evangelicals I've ever met have been either A) ex-Catholics themselves and likely bitter in the same way Catholics turned mainline/other religion/nothing usually are and/or B) liberal evangelicals that are against the church due its policies on women and gays. Granted I'm not the top guy to talk to for the opinions of conservative evangelicals, but once again, please look toward Rick Santorum's campaign.
You're pretty spot on actually. I mentioned this in the other thread on the issue, but the more political conservative-evangelicals tend to be, the more pro-Catholic they are. People who attend evangelical churches for cultural reasons (a good chunk of the evangelical community) see Catholics as brothers in arms more than anything.
Institutions like Wheaton, Fuller, Christianity Today, et al are pretty representative of evangelicalism as a whole, and I doubt you'd hear anything coming out of those schools or from that magazine that proclaims Catholics to be non-Christian. Hell, Billy Graham was considered the determining factor in whether or not one was a fundamentalist or an evangelical in the 50s, 60s, and 70s. What was the issue that caused fundamentalists to scorn Graham? He did his crusades alongside Catholics. C.S. Lewis is a revered figure in evangelical academia, and they all know he believed in purgatory, prayers for the dead, etc.
But of course it's the backwoods fundamentalist who says gays should be put in concentration camps that gets slapped with the "evangelical" label by the media, because they don't know any better. Evangelicalism, for what its worth, was always slightly left-leaning before a bunch of fundamentalists started calling themselves evangelicals and got involved in politics in the late 70s. Those fundamentalists morphed into what we call "conservative evangelicals" today, and they're largely concerned with politics more than they are with theology. It's only natural that they'd gravitate towards a guy like Santorum, because he's culturally conservative, their litmus test.