If McCain wins South Carolina tonight, he will probably win the Republican nomination.

There, I said it. 

Before you flood my inbox with hate mail, let's examine the evidence. After South Carolina, the Republican race moves to Florida on Jan. 29. Who's out front there? McCain, who leapt to the lead immediately after winning New Hampshire. He hasn't let go, even after losing Michigan to Mitt Romney. A month ago he polled at 10 percent; now he's up to 23. If the Palmetto State proves that New Hampshire wasn't a fluke, expect those numbers to climb higher--meaning that at that point it'll be up to Giuliani and Romney, both of whom need wins in the Sunshine State to stay viable, to knock the new frontrunner off his pedestal. If they fail, the Arizona senator will close out the first round of nominating contests with the wind at his back. I'm guessing that his (already sizable) 9.5 percent lead in the national polls will grow--and with only one week between Florida and Feb. 5, Republican voters spread across 21 states won't have a whole lot of time to change their minds (or have their minds changed by rival candidates). If McCain wins South Carolina, he'll probably clinch the nomination by the time the polls close on Super-Duper Tuesday.

Of course, the Arizona senator could very well lose tonight--in which case all bets are off. His lead in South Carolina over Mike Huckabee is razor-thin--just one point--and some have speculated that Huckabee's zealous evangelical supporters are more likely than McCain's aging veterans to brave today's cold, wet weather. If McCain takes the silver, he's right back where he started--in the middle of a muddled Republican pack. Without a frontrunner, Romney, Giuliani and a newly-victorious Huckabee would all have an equal shot at Florida.

And even I'm not reckless enough to predict what would happen next.