Cafeteria Catholic: One who, although professing to be a real Catholic, picks and chooses among the core Catholic beliefs much as one who would choose different food items while in a self-serve cafeteria. These Cafeterians typically attend mass two days each year - Easter and Christmas - and don't know their pastor's name. Cafeterians include those who profess any or all of the following beliefs: Pro-abortion, Pro-homosexual marriage, Pro-cohabitation, Pro-premarital sex.
If I'm not mistaken, we have quite a few politicians who fit this definition - some on the Republican side.
Make that three days, in some years: Christmas, Easter, and the Sunday before election day.