South Carolina: Polls close at 7 PM ET. Note that for any races in which no one wins more than 50 percent, a runoff will be held June 24.
• SC-Sen-A (R): Republican Sen. Lindsey Graham has been a tempting tea party target for years. Some of his actions, including his votes to confirm both of President Obama's Supreme Court nominees, have earned him the ire of grassroots conservatives. However, Graham has worked hard to shore up his right flank: He wasted little time bringing up Republican red meat issues like Benghazi and stressing his conservative credentials.
Graham has also benefited from a set of weak challengers. None of them are particularly well known and none have much money to spend compared to Graham. Outside conservative groups have also largely stayed out of the contest, further helping Graham. There has been very little recent polling here, but Graham looks favored to win the nomination Tuesday without a runoff.
Head over the fold for more races to watch on Tuesday.
Virginia: Polls close at 7 PM ET.
• VA-07 (R): House Majority Leader Eric Cantor faces a primary challenge in a race that has been getting a good deal of attention. Some tea party groups are hoping that college professor Dave Brat can upset the very establishment favored Cantor in a low turnout race. Cantor will be tough to beat but he isn't taking any chances. In the last seven weeks Cantor outspent Brat $993,000 to $76,000, and has aired ads hitting Brat. A Brat upset is very unlikely, but a relatively close race would make the Republican establishment nervous.
• VA-08 (D): Democratic Rep. Jim Moran's retirement has left his safely blue Northern Virginia seat up for grabs. Six credible Democrats are running, and the frontrunner looks like former Lt. Gov. Don Beyer. Beyer has a clear financial advantage over his opponents and his local car dealerships give him considerable name recognition. Beyer will face former Northern Virginia Urban League head Lavern Chatman; state Sen. Adam Ebbin; Alexandria Mayor Bill Euille; Del. Patrick Hope; and radio cost and former congressional aide Mark Levine. In a race this crowded, it's possible that one of them could pull off a surprise, but this race looks like Beyer's to lose.
Maine: Polls close at 8 PM ET.
• ME-02 (D & R): Democratic Rep. Mike Michaud is running for governor and leaving his Democratic-leaning but competitive seat up for grabs. State Sen. Emily Cain will face state Senate Majority Leader Troy Jackson in the Democratic primary. Both candidates are trying to portray themselves as the true Democrat in the race. Jackson is criticizing Cain over a 2011 budget deal she made with Republican Gov. Paul LePage; Cain in turn is hitting Jackson for his 2009 vote against same sex marriage and portraying him as an opponent of abortion rights.
Cain has outspent Jackson $182,000 to $83,000 in recent weeks and her allies EMILY's List and the League of Conservation Voters have also spent on her behalf. An unanswered poll from LCV also shows Cain with a massive 60-25 advantage in the primary. Jackson has been emphasizing populist economic issues and he does have a geographic base of support, but he looks like the clear underdog.
On the Republican side, former state Treasurer Bruce Poliquin faces former state Senate President Kevin Raye, who was also the party's 2002 and 2012 nominee. Poliquin has outspent Raye $234,000 to $111,000 in recent weeks, and has attacked Raye for refusing to sign an anti-tax pledge. However, Raye may have better name recognition from his past campaigns. Either Republican will have a tough time in the general in this 53/44 Obama seat, but neither can be counted out.
Nevada: Polls close at 10 PM ET.
• NV-04 (R): Freshman Democratic Rep. Steven Horsford had an unexpectedly competitive 2012 race, and Republicans are hoping to target him before he becomes entrenched. Two noteworthy Republicans are running: state Assemblyman Cresent Hardy, and Niger Innis, the spokesman for the once great but long-disgraced Congress of Racial Equality. Neither candidate has spent much in the last few weeks, and Horsford would start out as the favorite against either in this 54/44 Obama seat.
• NV-LG (R): Two credible Republicans are competing to face Democratic Assemblywoman Lucy Flores in a race that may have major long-term implications. Governor Brian Sandoval and other establishment Republicans favor state Sen. Mark Hutchison, who represents a Las Vegas-area swing district. Hutchison's primary foe is former state party chair and 2010 US Senate candidate Sue Lowden. While Hutchison has raised more money, Lowden has outspent Hutchison $293,000 to $170,000 in the last three weeks of the race. Both candidates are trying to paint the other as insufficiently conservative, and the race has gotten quite negative.
The lieutenant governor's office is not particularly powerful, but the primary and general elections are very important this year. Sandoval is expected to easily win re-election and is seen as Democratic Senate Majority Leader Harry Reid's toughest potential challenger in 2016. However, Sandoval may be reluctant to run if his victory meant ceding the governorship to the Democrats. Team Red's odds of keeping the lieutenant governorship would be diminished if Lowden, who helped destroy her 2010 Senate campaign with the infamous chicken-for-checkups gaffe, won on Tuesday. Hutchison looks like the favorite in the primary but Democrats would love a surprise. In any case, Reid is expected to do whatever it takes to help Flores win in November.
• Statewide positions: In South Carolina, four Republicans are competing in the open lieutenant governor's race, while nine Republicans and four Democrats are running for state Superintendent of Education. In Arkansas, Republican attorneys Leslie Rutledge and David Sterling are competing in the runoff for attorney general. The winner will take on Democratic state Rep. Nate Steel in what is expected to be a competitive general election. In Nevada, three Republicans are running for state controller. The winner will face Democratic state Assemblyman Andrew Martin.