Jaweed Kaleem, writing at the Huffington Post, has an in-depth article on Gingrich's conversion to Catholicism. Of course, it would be nice to see the former speaker come to a better appreciation of the rich tradition of Catholic social teaching, and how it varies greatly from the more libertarian strands within the GOP today. But, as I wrote at the time of his reception into the Church, it is a big church and there is room for everybody.
Kaleem's article also demonstrates that the conversion was not, by all acounts, a matter of political expediency. It grew, as many conversions do, out of his growing familiarity with the religion of his wife. In my involvement with RCIA, we often have several converts who come to the Church for the same reason. Nor is it clear that being Catholic provides any particular benefit politically. Like his opponent Mitt Romney, Gingrich's views should be a matter of debate, not his faith.