Marc Ambinder has a noteworthy post on a possible GOP primary scenario that may result in the race continuing through March:
Mitt Romney wins Iowa; Mike Huckabee is second; Rudy Giuliani is third; Fred Thompson is fourth.
Giuliani wins New Hampshire, followed by Romney or Huckabee or McCain.
Romney wins Michigan; Huckabee or McCain is second.
Thompson wins South Carolina, followed by Giuliani. Romney is third.
Florida will be extremely competitive on Jan. 29.
The candidates split the Feb. 5 states, with Giuliani running the table in the Northeast, Thompson taking the South and Romney picking up Arizona and winning delegates in proportionally allocated states elsewhere.
The media isn't sure which candidate to pressure to drop out; Romney will have enough money to compete, Giuliani may have a delegate lead, and Thompson is clearly the favorite son in the deep South.
Could March 4 be the filter? That's when Ohio and Minnesota - two big Midwestern swing states - not to mention Vermont and Massachusetts - hold contests.
While contemplating this scenario, it's important to remember that the primaries are a dynamic process. A Romney win in Iowa would have a dramatic effect on the public perceptions in other states of the former governor's chances, and may elevate his chances of winning in southern states. If Iowa is close, and if Giuliani has a decisive victory in New Hampshire, then it's hard to see why Giuliani wouldn't place at least in the top three in Michigan.
Also: I wouldn't count out Ron Paul from placing in the top three in New Hampshire. This is American politics, after all. Stranger things have happened.