(CNN) - The midterm election season officially gets underway Tuesday, as Texas holds the first primary contests of 2014.
Tea Party vs. Establishment
A top House Republican faces a tea party challenge in Tuesday's primary. Grassroots conservative activist Katrina Pierson is taking on Rep. Pete Sessions, a nine-term congressman and chairman of the powerful House Rules Committee.
Pierson won the backing of top national groups such as the Tea Party Express, the Tea Party Patriots and FreedomWorks, as well as influential figures on the right such as former Alaska Gov. Sarah Palin and conservative firebrand Rafael Cruz, the father of Sen. Ted Cruz of Texas.
Despite her impressive list of endorsements, Pierson's fundraising lags far behind that of Sessions, the odds on favorite in the race. Sessions, who represents the Dallas area 32nd Congressional District, is one of eight GOP House leaders or committee chairs nationwide who face primary challenges this year.
Challenges from the right
Sen. John Cornyn faces a number of conservative primary challengers. The most well-known of the candidates is Rep. Steve Stockman. But Cornyn, the No. 2 ranking Republican in the Senate, doesn't appear to face much of a threat Tuesday.
But Cornyn has had to alter tactics since the 2012 election of Ted Cruz, who's become a hero to grassroots conservatives. Cruz has put Cornyn and other members of the Senate GOP leadership on the defensive a number of times over some key issues.
While most pundits expect Cornyn to top the 50% threshold needed to avoid a runoff, look for his margin of victory to gauge anti-incumbent sentiment.
Cornyn is one of 12 Republican senators running for re-election this year, and half, including Senate GOP leader Mitch McConnell of Kentucky, face conservative primary challenges. While neither McConnell nor Cornyn expect to face difficult primaries, some other senators, such as Thad Cochran of Mississippi and Pat Roberts of Kansas, might face bigger challenges.
Preview for big gubernatorial showdown
Turnout in the gubernatorial race could be an indicator of what's to come in the showdown between Republican Attorney General Greg Abbott and Democratic state Sen. Wendy Davis, the two likely nominees in the governor's race.
Battleground Texas, a group aiming to turn the Lone Star State blue, has been working on get-out-the-vote efforts for Davis, hoping to make Republicans sweat as the state moves closer to the general election.
The race is already one of, if not the, most expensive gubernatorial contest in the country. Abbott's campaign reported having nearly $30 million cash on hand last week, while Davis' team reported having $11.3 million. Davis, however, raised slightly more than Abbott in the reporting period from January 24 to February 22.
The next generation Bush
Other statewide races worth watching include the primary for Texas land commissioner, a job George P. Bush has been gunning for this past year. Bush is the son of former Florida Gov. Jeb Bush, nephew of former President George W. Bush and grandson of former President George H.W. Bush.
Coming from a strong political family, however, doesn't protect one from opposition. Bush, who's considered the favorite, will face off against conservative David Watts.
Nonetheless, the primary marks Bush's first big contest as he launches what many political observers expect to be a must-watch career in politics.
Another tough contest for Dewhurst
Perhaps the most vulnerable incumbent Tuesday is Lt. Gov. David Dewhurst, who's in a tight race with state Sen. Dan Patrick. If neither candidate exceeds 50%, they enter a run-off set for May 27.
Dewhurst, who lost the 2012 run-off for the U.S. Senate against Cruz, may find himself again in an extended primary race.
Age in the spotlight
At the age of 90, Republican Rep. Ralph Hall is the oldest member of the U.S. House. He faces a difficult road to re-nomination, with five challengers taking him on in the primary. And most of them are arguing that after Hall's more than three decades in the seat, it's time for new representation in the state's 4th Congressional District.