The Texas Republican Party is reopening the filing period for Rep. Steve StockmanStephen (Steve) Ernest StockmanEx-GOP staffer pleads guilty to fraud, money laundering on behalf of ex-lawmaker Cornyn to run for reelection in 2020 Former congressman indicted on conspiracy charges MORE's (R-Texas) congressional district after his last-second decision to run instead against Sen. John Cornyn (R).

Stockman filed for Cornyn's seat rather than reelection just minutes before the state's legal filing deadline Monday night, giving aspiring politicians in the district no heads up that he was doing so. The party's move gives candidates an additional week, with the new filing deadline set for next Monday.

Texas Republican Party spokesman Spencer Yeldell said the party was reopening the filing because it's required by Texas's election code.

Stockman is facing a steep uphill battle for the Senate seat. His district is heavily Republican — the winner of the primary would likely succeed him in Congress.