Primary primer

Twelve states are voting Tuesday — here's a quick cheat sheet for when polls close and what races to watch:

7 p.m. EST: The first round of polls closes, with races being decided in Georgia, South Carolina and Virginia.

Georgia will decide which Republican it will send to Congress in the special election to replace Rep. Nathan Deal (R-Ga.), who has resigned to run for governor. Former state Rep. Tom Graves and state Sen. Lee Hawkins advanced to Tuesday's runoff after last month's election failed to produce a majority-candidate. It's no surprise Republicans will hold on to this district, one of the most conservative in the country.

In South Carolina, all eyes will be on the governor's race, where state Rep. Nikki Haley is fighting for the Republican nomination. She's the favorite in the race and has the support of both Sarah Palin and Jenny Sanford, but a few weeks ago a conservative blogger alleged he had an extramarital affair with Haley — a charge she denied. A Public Policy poll released Monday had her leading her nearest GOP competitor by 20 points.

In Virginia, Republicans will be waiting to see who wins the nomination to face freshman Rep. Glenn Nye (D-Va.), who is a top GOP target. Scott Rigell is the party favorite but he's been under attack by the Tea Party. It'll be interesting to see if this primary goes the way of GOP primaries in Idaho and Kentucky, where the Republican Party favorite lost to a Tea Party candidate in both races. And seven candidates are vying for the GOP nomination to take on Democratic Rep. Tom Perriello, another leading GOP target.

8 p.m. EST: Maine and New Jersey

There's an open governor's race in Maine; in New Jersey, it'll be worth watching to see if former Philadelphia Eagles player Jon Runyan wins the Republican nomination to face freshman Rep. John Adler (D-N.J.). Runyan is the party favorite but has been struggling.

8:30 p.m. EST: Arkansas

It's the biggest race of the night. Will Sen. Blanche Lincoln (D-Ark.) become the next lawmaker to fall to anti-incumbent fever? Unions have spent more than $65 million to help Lt. Gov. Bill Halter (D-Ark.) take her down, and the Democratic establishment has thrown its weight behind Lincoln.

9 p.m. EST:  North Dakota and South Dakota

Sen. Byron Dorgan (D-N.D.) is retiring but the primary races to replace him are not competitive.

10 p.m. EST: Iowa, Montana and Nevada

The second biggest race of the night is in Nevada, where both parties will wait to see who'll face Senate Majority Leader Harry Reid (D-Nev.) in November. Sue Lowden is the Republican Party favorite but she's recently come under heavy fire and Tea Party candidate Sharron Angle has pulled ahead in the polls. A Mason-Dixon poll released Sunday had Angle up by eight points and Lowden finishing third. Reid looked vulnerable earlier this year but his poll numbers have been slowly improving — perhaps thanks to all the GOP infighting during the primary campaign.

And it's worth keeping an eye on the Republican gubernatorial primary for the personalities involved. Republican Gov. Jim Gibbons went through a very nasty public divorce and was down 14 points in Sunday's Mason-Dixon poll.

11 p.m. EST: California

Three Republicans are fighting to take on Sen. Barbara Boxer (D-Calif.) A Survey USA poll released Tuesday had former Hewlett-Packard CEO Carly Fiorina up by 26 points. Fiorina has invested millions from her personal fortune into her campaign.

There's also a competitive primary for the GOP gubernatorial nomination, but it's often overlooked by the more-competitive Senate race. Between the two of them, former eBay CEO Meg Whitman and state insurance commissioner Steve Poizner have sunk at least $100 million of their own money in the race. It's a lot of money to pay for the right to face the Democratic nominee, Attorney General Jerry Brown, who served as governor in the '70s and '80s. A Survey USA poll Tuesday had Whitman up by 29 points.