In today's Washington Post, Michael Gerson does a good job outlining why Rudy Giuliani's culture-war overtures to the right don't constitute social conservatism in any meaningful sense. It ought to give thoughtful social conservatives pause. Though I think it would have been fair to acknowledge that Mayor Giuliani's economic record in New York City was more conservative than "Nixonian."
It's also worth noting that social conservatives voted for Richard Nixon.