In Alaska (see all candidates [3]), two members of Congress, both Republicans and both under federal investigation, face formidable primary challenges Tuesday. Down in Florida there are primary candidates running in each of Florida's 25 congressional districts (see all candidates [4]).

Alaska Rep. Don Young [5] is facing two Republican challengers: State Representative Gabrielle LeDoux [6] and Lieutenant Governor Sean Parnell [7], who is backed by the much of the state party's establishment. On the Democratic side, former State House Minority Leader Ethan Berkowitz [8] and Diane Benson [9], who nearly beat Young in 2006, are running.

It's a little unclear, but Young may be under a Department of Justice investigation for a $10 million earmark benefitting one of his campaign contributors [10] in Florida that was mysteriously inserted into a bill after it was passed. However, Young is definitely under federal investigation for his connections to the same oil company bribery scandal [11] that ensnared Sen. Ted Stevens [12] (R) in corruption charges earlier this month.

Stevens is facing his own tough primary challenge from a raft of Republican candidates including Dave Cuddy [13], Jerry Heikes [14], Rick Sikma [15], Ray Metcalfe [16] and Vic Vickers [17]. On the Democratic side, running are Nels Anderson [18], Rocky Caldero [19], Frank Vondersaar [20] and Mark Begich [21], the front runner. And we'd be remiss to leave out Libertarian David Hase [22], Veterans Party of Alaska candidate Ted Gianoutsos [23] and Alaska Independence candidate Bob Bird [24].

Turnout appears light in Florida, which is still enduring Hurricane Fay-caused blackouts and has no statewide races on the ballot.

The AP reports [25] that the race to watch is in the 16th congressional district, where Republicans Gayle Harrell [26], Tom Rooney [27] and Hal Valeche [28] are vying for the nomination to challenge Democratic Rep. Tim Mahoney [29] in November. Mahoney won the seat in 2006 after former Rep. Mark Foley [30] (R) resigned in September of that year in the wake of a scandal on inappropriate contact with House pages [31]. Mahoney looks especially vulnerable since he won the 2006 race by only one percentage point despite Foley's name remaining on the ballot.

The only open seat in Florida is the 15th district's, where Rep. Dave Weldon [32] (R) is retiring and a large pool of candidates have stepped up for their parties' respective nominations. Running are Bill Posey [33] (R), Alan Bergman [34] (R), Kevin Lehoullier [35] (R), Trevor Lowing [36] (R), Steve Blythe [37] (D), Paul Rancatore [38] (D) and Frank Zilaitis [39] (I).