Rep. David Schweikert (above) faces fellow freshman Rep. Ben Quayle in today's Arizona primary battle for the 6th district GOP nomination.
Arizona's 5th district
Former Rep. Matt Salmon (R) is widely expected to win this primary and as a result return to Congress in the fall.
But his primary rival, former state Speaker Kirk Adams, has unleashed a fascinating barrage of endorsements in the final weeks of the campaign. Palin even trekked to Arizona to campaign for Adams on Monday.
Salmon is seeking to return to Congress after a 12-year sabbatical to honor a 1990s term-limit pledge. Salmon has strong name identification, the Club for Growth behind him and the financial edge.
This seat most closely resembles Flake's current district. Flake endorsed Adams last week.
Arizona's 6th district
This is the race to watch tonight.
It took a while, but the primary for the new 6th district is among the nastiest Member-vs.-Member contests of the cycle.
Because freshman GOP Reps. Ben Quayle and David Schweikert share solid conservative voting records, the campaign has focused on the personal. The accusations have been vicious and relentless.
Most unaligned operatives in the state, and national handicappers, predict Schweikert will come out ahead. Still, one national Republican cautioned that Quayle has a team that is especially adept at getting out the vote.
Before this Member-vs.-Member race came to be, both Members were talked about as future Senate candidates.
Arizona's 9th district
Races elsewhere in the state have overshadowed what will be a fall tossup race, and Democrats are energized.
But there is little consensus on either side as to who will win today's primary.
An unscientific gut check of Arizona Democrats says that former state Sen. Kyrsten Sinema has the best chance of winning their party's nomination. Still, she has had stiff competition in her primary. One Democratic strategist has gone so far as to call the crowded field "an embarrassment of riches."
Former state party Chairman Andrei Cherny is also in the hunt for the nomination, and he has the valued and effective endorsement of Bill Clinton. State Sen. David Schapira has run an underfunded but respected campaign.
On the Republican side, most have assumed former Paradise Valley Mayor Vernon Parker will win, but the GOP field is crowded and underfunded. Like the Democratic side, public polling is scant, so anything could happen. Other contenders are ex-Chandler City Councilman Martin Sepulveda, businessman Travis Grantham and retired Air Force officer Wendy Rogers.
Oklahoma's 2nd district
In two primary runoffs, seed company owner Wayne Herriman and former District Attorney Rob Wallace are seeking the Democratic nomination, and plumbing company owner Markwayne Mullin and state Rep. George Faught are facing off for the GOP nod.
The 2nd district includes reliable GOP territory, and Roll Call rates this race as Leans Republican.
Rep. Bill Cassidy has his blood drawn by Alesha Barbour during a free hepatitis screening in the Rayburn House Office Building hosted by the Congressional Viral Hepatitis Caucus to recognize "National Viral Hepatitis Testing Day."
Roll Call has launched a new feature, Hill Navigator, to advise congressional staffers and would-be staffers on how to manage workplace issues on Capitol Hill. Please send us your questions anything from office etiquette, to handling awkward moments, to what happens when the work life gets too personal. Submissions will be treated anonymously.