Let us please keep in mind here (as I don't think Maher does), that there is a difference - often a large difference - between a conservative and a right-winger. The one should not be confused with the other. Nor does being Republican mean that one is on "the right" either.
The right-wing, as I understand the term, applies to militia groups, people who think that Obama was born in Kenya, Fred Phelps, the late Jerry Falwell, people who think Climate Change is a liberal conspiracy, and other such radical loonies.
The right-wing has become absurdly extreme and very dangerous. There are, however, a great many thoughtful conservatives and moderates, many of whom are Republicans, I want to stress that, at least for me, the right-wing is the danger, not all Republicans are all conservatives.