Of course they have. Last election they stayed home in droves. And this time around they’re fully fed up and jumping ship.
78% of evangelicals who turned out voted for Romney, a net increase over the same who voted for McCain/Palin.
http://www.washingtonpost.com/wp-srv/special/politics/2012-exit-polls/table.html
The GOP doesn’t have an evangelical problem. They have a spine problem regardless who is in the White House.