I don't believe I've ever seen him quote Scalia. If the best he's got is a squishy swing voting moderate like O'Conner, he can keep her just the same.
He quotes Washinton, Madison, and Jefferson, and attempts to use them to argue from a historical context.
I have only rarely seen him quote Jefferson before, largely because many of Jefferson's quotes were in direct conflict with The Lincoln's actions. He does seem to quote Washington fairly frequently, though almost always out of context or in a situation where he claims Washington to have said something that he didn't (Normally this consists of taking any and every quote that mentions the word "union" in any context whatsoever and declaring, based solely upon the presence of that word, that it must have meant The Lincoln's concept of the union). He does the same with Madison, though on a less frequent basis.