John McCain, Newt Gingrich, Tom DeLay, Joe Lieberman, and Rick Santorum (who is Catholic) have all appeared with John Hagee. And that's just from my personal recollection and some cursory googling -- I'm sure the list of politicians who have appeared with Hagee is even longer. None of them did so because of anti-Catholicism. They appeared with Hagee because of his leadership in Christians United for Israel. President George W. Bush gave a welcoming statement to the group's Washington Summit earlier this year. Hagee has advised Texas Gov. Rick Perry on divestment from Iran.
I'm no Hagee fan myself, but let's be honest: By appearing at Cornerstone Church, Mike Huckabee is trying to appeal to that constituency -- conservative evangelicals and other Christian Zionists -- not the miniscule anti-Catholic vote. If Hagee's theology or other views make him beyond the pale, then there are a lot of politicians who should be condemned.