The remnants of the Republican Party, left in tatters, subsequent to the so-called Tea Party Movement manifestation. The Left Behind Republican Party is constituted of the leftovers, the politicians who were simply too single-minded and too corrupt to change over. As a result, there are now TWO Republican Parties. The Left Behind facet is a double entendre allusion to the popular book and film series, Left Behind, which focuses on the Christian Fundamentalist doctrine of "The Rapture".
The Left Behind Republican Party will certainly not earn Mitt Romney's endorsement since he believes in Women's Rights, or at least says that he does.