Texas Rep. Joaquin Castro (D) is considering giving a House re-election bid a pass next year and, instead, taking on the senior Senator from the state, Republican John Cornyn.

On Friday, the Texas Tribune reported that a source close to the four-term congressman said he is likely to make the run. Castro's campaign adviser, Matthew Jones, told the Tribune his decision about next year will be coming "in the near future."

Texas Monthly reported on Friday that a run against Cornyn is "all but certain" according to "a source familiar with Castro's thinking."

Former San Antonio mayor and former Obama HUD Secretary Julián Castro, the congressman's twin brother, is an already declared candidate for the 2020 Democratic presidential nomination.

Also from Texas, former Rep. Beto O'Rourke is running for the Democratic nomination, he announced this week. O'Rourke ran for the other Texas Senate seat against Republican Ted Cruz last year and, despite a heady media love affair, lost.

Although defeating Cornyn represents an uphill climb for Castro, the expectation is that his run would create another major media blitz.

Cornyn's campaign manager says the senator is ready.

"Whether it's Hurricane Harvey relief or the Green New Deal, time and again Congressman Castro has stood with Nancy Pelosi at the expense of Texans," John Jackson said in a statement. "John Cornyn looks forward to contrasting the Democrat-Socialist agenda with the policies that have made Texas the best state to live, work, and raise a family."