What comes after New Hampshire?
The next primary is Tuesday in Michigan, but it won't be a race among the Democrats. Because of a dispute over the timing of the election, Hillary Clinton is the only major candidate on the ballot, and she will not be campaigning in the state.
For Republicans, however, Michigan will be a key test for Mitt Romney. He's a native, and his father served as governor, so a loss there could further damage his campaign.
On Saturday, Jan. 19, Democrats will hold caucuses in Nevada, a key state for organized labor and Hispanics. The state's powerful Culinary Workers Union is expected to endorse Obama, but John Edwards has been courting unions there as well.
For both parties, South Carolina looms just over the horizon. Republicans will face off there on Jan. 19, with John McCain hoping to avoid the kind of devastating loss he suffered to George W. Bush there in 2000.
Democrats will face off in the Palmetto State the following Saturday, Jan. 26.
