7:00pm: Polls close in Georgia where both parties are holding contests. There are 87 delegates at stake for Democrats, 72 for Republicans. Georgia has no party registration, meaning any voter can participate in either party's primary. This should be a big state for Barack Obama -- -in 2004, nearly half the Democratic primary electorate was made up of black voters. This will be a good test of where conservative voters are leaning among the Republican field.
8:00pm: This is the big one as polls close in Alabama, Connecticut, Delaware, Illinois, Massachusetts, Missouri, New Jersey, Oklahoma, Kansas (Democrats only), Minnesota and Tennessee. There are a wide geographical variety of states at play here.
On the Democratic side, Obama's home state closes at this hour as well as potential battlegrounds in Connecticut, Massachusetts, New Jersery and Delaware. Because of the proportional distribution rules of the Democrats, winning a majority of these states does not necessarily mean big delegate wins. Keep an eye on that delegate count as it begins to come in throughout the evening to get a better idea of where the race is. The big one to watch at this hour is Missouri, a critical general election state. Whoever "wins" the state will have a measure of bragging rights.
On the Republican side, we have some big winner-take all states that should give John McCain a jump-start on the evening. A northeast sweep by McCain in New Jersery, Connecticut and Delaware (and a hard-fought fight in Mitt Romney's home state) would put McCain out front among delegates. Watch the southern states for signs of whether Huckabee is eating into Romney's share of the conservative vote. And for Republicans, Missouri will also be one of the major battlegrounds of this hour, its winner-take-all rules will be a huge win for either McCain or Romney.
Minnesota and Kansas are caucus states and start at 8:00pm.
8:30pm: The polls in Arkansas close. While there is a relatively small cache of delegates at stake for both parties, losses here would be embarrassing for Clinton, the state's former first lady or Huckabee, its former governor.
9:00pm: Arizona, Colorado, Idaho, New Mexico (Democrats only), New York and Montana (Republicans only).
Of these states, only Arizona and New York are conducting state-run primaries, the rest are caucuses or party-run primaries. Colorado and Idaho are listed by start times.
New York will be the jewel here for both parties. McCain could take the state's 87 delegates awarded on a winner-take-all basis. Clinton should win easily here, but once again the proportional rules could allow Obama to walk away with a large chunk of his own. Both Obama and Romney have spent a good deal of effort in the caucus states, watch New Mexico for the Hispanic vote.
10:00pm: North Dakota and Utah. Should be a big win for Romney in a state with a large Mormon vote and both have been targeted by Romney and Obama.
11:00pm: The big enchilada, California closes. This is the biggest contest by far for both parties, with a total of 441 Democratic delegates at stake and 173 for Republicans. Not only will is this the biggest in terms of delegates but also for bragging rights. Sizable wins here for a candidate (most in both parties are allocated by Congressional District) would cap off the night right. Most expect the Democratic race to remain fairly close at the end of the evening but California could have a big impact on the GOP race. A win here by Romney would help balance victories by McCain in states like New York and New Jersey. Should he run the table here though, McCain may be on his way to the nomination.
11:30pm Alaska's caucuses close, giving the land of the midnight sun the final say on this superest of Super Tuesdays.