“I am announcing that I will be a candidate for president of the United States.” With Rudy Giuliani pulling ahead in the still-relatively-useless name game polls, the former captain of the Straight-Talk Express, John McCain, tells David Letterman he’s in for 2008. So…Clinton, Obama, Giuliani and now McCain: With a little less than a year before the first primary, the field of major contenders now seems to be set. Gentlemen (and gentlewoman), start your begging.