It's the biggest primary day of the year -- ten states, plus runoffs in Arkansas (Senate) and Georgia (House). And while there will be different themes developing throughout the country, here's what you should be keeping your eye on:
Women: Republican women are favored to win primaries for the Senate and governor in California. Both are wealthy, mostly self-financed businesswomen who are making their first foray as candidates -- part of the "anti-establishment/anti-Washington" theme we've been watching this year. A woman may well emerge as the GOP nominee for the Senate in Nevada, and a woman is leading the pack in the Republican primary for governor of South Carolina. In addition, Democratic women lead in the primaries for the Senate in Iowa and the governorship in Maine.
An exception to this "Day of the Woman" motif may come in the Democratic Senate runoff in Arkansas. This also fits in with the anti-establishment theme mentioned above.
Tea Party: They scored a huge victory last month with Rand Paul's win in the Kentucky GOP Senate primary, and they're looking for more gains tonight, especially in the Nevada Senate race.
Memory Lane: Terry Branstad, an Iowa Republican who served four terms as governor (1983-98), is seeking a comeback. In California, Jerry Brown -- who was twice elected governor in the 1970s and who is the current state attorney general -- is all but assured of the Democratic nomination for his old job. Change we believe in?
Here are the poll closing times (all times Eastern):
7 p.m.: Georgia, South Carolina, Virginia
8 p.m.: Maine, New Jersey
8:30 p.m.: Arkansas
9 p.m.: North Dakota, South Dakota
10 p.m.: Iowa, Montana, Nevada
11 p.m.: California
There's also that 7 p.m. debut for Stephen Strasburg at Nationals Park. I suspect that might attract more interest, certainly in Washington, than some of the primaries listed above.