For Democrats, the caucuses could determine a front-runner. Iowa is a chance for the campaigns of Barack Obama or S.C. native John Edwards to shatter Hillary Clinton's aura of inevitability; a Clinton win could squelch the upstarts.
For Republicans, the results are most important to Mitt Romney, Mike Huckabee and Fred Thompson. Poor showings by any of them could end their campaigns. The GOP field likely will remain muddled after Iowa. Romney and John McCain will square off in New Hampshire. That sets the stage for South Carolina, which has picked the past four GOP nominees.
• Jan. 8 -- New Hampshire holds its Democratic and Republican presidential primaries.
• Jan. 10 -- Fox News will televise GOP presidential debate from Myrtle Beach.
• Jan. 19 -- S.C. Republican presidential primary will be held.
• Jan. 21 -- CNN will televise Democratic presidential debate from Myrtle Beach.
• Jan. 26 -- S.C. Democratic presidential primary will be held.
Latest poll numbers
The Des Moines Register poll shows the Democratic race like this:
U.S. Sen. Barack Obama of Illinois, 32 percent;
U.S. Sen. Hillary Clinton of New York, 28 percent;
Former U.S. Sen. John Edwards of North Carolina, 24 percent.
Results show Obama surging, Clinton and Edwards holding steady.
Former Arkansas Gov. Mike Huckabee, 32 percent;
Former Massachusetts Gov. Mitt Romney, 26 percent;
U.S. Sen. John McCain of Arizona; 13 percent.
Huckabee and McCain have gained support.
The poll was taken Dec. 27-30; it questioned 800 likely GOP caucusgoers and 800 likely Democratic caucusgoers.
What does Iowa caucus mean to S.C.?