but I don't think many Republicans would say that McCain was a better politician than Obama.
Oh, I know that I certainly wouldn't.
Obama's a freakishly skilled politician -- maybe even moreso than Bill Clinton was. They both kind of came out of nowhere. But Obama's rise was far more meteoric than WJC's was. WJC had been involved in state-level politics in Arkansas for a long time and was a known quantity in the political class in 1992. But few people knew him outside his own state -- at least when compared to his rivals in the 1992 primary. Clinton quickly stood out from his competitors though -- he had more ability to "connect" with voters than the other guys combined.
Obama, on the other hand, went very quickly from backbencher state senator in Illinois to POTUS -- with only a brief stop as a US Senator along the way. And it was his keynote address at the 2004 Democratic National Convention that propelled that rise. Whoever was responsible for choosing him for that slot knew very well what kind of phenom they had on their hands in Obama. Not only did he have the presence and communication skills -- along with plainly obvious intelligence -- that probably even outpaced Clinton, he was also multi-racial -- which was a terrific fit for a Democratic Party (and, for that matter, a country) that had become less and less white.
In terms of sheer political talents, Barack Obama is to John McCain as lightning is to a lightning bug.