The escalating political fight over the Texas congressional map is spreading across other states across the country, triggering an unprecedented mid-decade redistricting arms race with the balance of power in Washington at stake.

Trump is also actively involved in recruitment efforts and intervening early with endorsements to head off messy GOP primary fights in the House and Senate, which could soak up money and energy ahead of general elections. In past cycles, Republicans botched some races by nominating contentious candidates backed by Trump that lost winnable races.

Texas Gov. Greg Abbott called a special legislative session that would, if successful, shrink the number of Democrats the state sends to the U.S. House by five. That would leave Democrats with eight seats, roughly 20% of the 38 Texans there, despite Democratic nominee Kamala Harris netting more than 42% of the vote in Texas last year.

Texas House Democrats left the state Sunday in a desperate bid to block an aggressively partisan redrawing of the state’s congressional map orchestrated by Republicans with the support of President Donald Trump.