Most American Catholics apparently think the Democrat Party is the same party that ran Harry Truman.
One can simply no longer be a Christian nor a Patriot and vote for the Democrat candidate for anything. Furthermore, IMNVHO, this explains the disgustingly low turnout among otherwise good people. They cannot bring themselves to vote for Dear Old Dad's Democrat Party, but neither can they bring themselves to vote any other way. Result? They stay home. They are the "Reagan Democrats." Unfortunately, they have found no one else to overcome the inertia.
As far as I am able to tell, the Catholic clergy itself tends Democrat. 53% of Catholics voted for a late term abortion supporter for President. What % stayed home?
Its also a failure of clear teaching. The Bishops failed to excommunicate but Catholic institutions have also failed. In the 1980’s Cardinal O’Connor was fighting a heroic fight against the abortionists and was dueling with Mario Cuome ( who he failed to excommunicte). The Jesuits historically had been the intellectual sword of the Church and were expected to give O’Connor tactical support. Sadly the Jesuits at Fordham did virtually nothing to help him and in fact undercut his efforts. The Jesuits have devolved into an unspeakable lot. The biggest scam going is when Catholic parents pay $60,000 per year sending their kids to a Jesuit college for “a Catholic education”.
This 4% doesn't translate directly into Obama's 4% margin of victory in 2012, but better poll-crunchers than I are also scratching their heads. A friend remarked that Evangelical contacts who voted for McCain in 2008 stunned him in 2012 with announcements that they were not voting. He says a dozen Christian leaders were touting a new found “Christian Ethic” of not voting. “Not Voting, is a vote for Jesus!” to quote just one guy's Facebook page.
Am I blaming white Evangelicals for Obama's 2012 electoral success? No, it was fully a product of Evangelicals, Mainline Protestants, Catholic, Jews, secular-agnostics and aheists, of all ages, both sexes and all races, acting or failing to act more or less as expected.
There really weren't any big switches between 2008 and 2012... except that confounded increase in non-voters.