He has said many times he did convert from being a Catholic. At that, there is a video floating around of an interview a few years back where he described his conversion.
Of course, not that it matters. Not like his Catholicism or Mormonism effects any of our liberty. As long as he is free to choose his faith, so are we.
no religion on earth ranks wealth higher on the godliness scale than Mormonism...
I say that along with saying I'm voting for Romney no matter what his religion...