It occurs to me that a lot of the semi-baffled discussion of how Rudy Giuliani's been able to maintain his lead in national GOP primary polls has a tendency to implicitly overstate Rudy's actual level of support. His lead is real, and since the McCain Collapse has been consistently pretty large, but in absolute terms he's not a very popular choice for Republicans — only able to gain support from more than a third of Republicans for a brief and transient moment. Even though Giuliani's strong showing has surprised a lot of people, I don't think anyone would have been especially shocked two or seven years ago by the contention that 25 percent or so of Republicans aren't especially committed to the abortion issue. Rudy's lead is perfectly consistent with only a tiny number of actual "values voters" actually deciding that perpetual war is more important to them than banning abortion of persecuting gays and lesbians.
Meanwhile, the same considerations highlight the continued underlying weakness of Giuliani's candidacy. The graph seems to suggest that there's a reasonably firm ceiling on Giuliani's potential level of support. Ordinarily, what you'd expect to see happen is for various other contenders to drop out of the race as the primary season continues eventually leading to the emergence of an Anti-Rudy who picks up something like the combined McCain-Romney-Thompson-Huckabee vote in the current national polls (Ron Paul's clearly running a protest campaign and can be expected to stay in 'till the end) and wins the race. There's a question as to whether quirks of the process this year and the compressed schedule can prevent that from happening, but the basic reality is still that Giuliani's lead has more to do with the large number of flawed rivals in the field than with any overwhelming strength on his part.
Matthew Yglesias is a former writer and editor at The Atlantic.