If Trump appoints U.S. Reps. Hensarling and McCaul, who would replace them?

_{*Editor's note: This story has been updated.}

WASHINGTON — U.S. House special elections are rare in Texas politics, but the state may be getting two in the near future.  

Republican U.S. Reps. Jeb Hensarling of Dallas and Michael McCaul of Austin are reportedly in contention to serve in a Trump Cabinet. 

GOP sources tell the Tribune that McCaul is intrigued with serving as secretary of the U.S. Department of Homeland Security, and he’s also considering a challenge to U.S. Sen. Ted Cruz. If the latter were to occur, that would delay an open-seat scenario until 2018. 

Hensarling is less clear about his interest, but his name was floated as a possible secretary of the Treasury Department, and he would be serving in an administration with a close friend: Vice President-elect Mike Pence. 

There are a handful of people being talked about as contenders for the seats that would open up if the two Texans are appointed and confirmed. Both seats would almost certainly remain in the GOP column. This is an early look — more contenders could surface — and it's based on interviews with about a dozen Texas GOP operatives and officeholders.

Texas Gov. Greg Abbott would call a special election. To win, a candidate would need to secure a majority of the vote, either in the first round of voting or in a runoff. 

The seat: 10th Congressional District

McCaul’s 10th district includes the western Austin suburbs, cuts through the city, follows east out to the rural areas that include Brenham and La Grange and stops in Katy. 

This race would take on particular interest because of its proximity to the state’s political class in Austin. Furthermore, at least part of the would-be special election would likely take place during next year’s legislative session, adding another layer of political excitement.  

It would also be expensive: An election here would mean a likely television advertising campaign in both the Austin and Houston media markets.  

The potential contenders: 

• State Rep. John Cyrier, R-Lockhart
• Brian Haley, an Austin oil and gas investor and former staffer on John McCain's presidential campaign 
• Texas Public Policy Foundation board member Stacy Hock
• State Rep. Jason Isaac, R-Dripping Springs
• Communications consultant Jenifer Sarver of Austin 

The seat: 5th Congressional District  

Hensarling’s 5th District takes in parts of East Dallas, Mesquite, then follows the Trinity River deep into East Texas and includes Canton, Athens, Jacksonville and Palestine. 

The population center is in Dallas, giving an advantage to a Metroplex contender. But the candidate would probably also need to appeal to the many Trump voters of the Piney Woods. This, too, would be an expensive race because part of it is in the Dallas-Fort Worth media market. But part of it is in another market, Tyler, which is far less expensive.

The potential contenders:

• Outgoing state Rep. Kenneth Sheets of Dallas
• State Rep. Cindy Burkett of Sunnyvale 
• Mesquite City Councilman Greg Noschese

Read related Tribune coverage:

• Throughout his campaign, Trump relied on a relatively small but loyal group of allies in Texas, and now some appear poised to reap the benefits with a one-way ticket to Washington, D.C.
• Throughout his campaign, Trump cultivated a number of loyal allies in Texas, making for no shortage of options as his transition team looks to staff the incoming administration.