The battle between states attempting to redraw congressional maps mid-decade is now being called the “redistricting war.” The results could upend the midterm elections and determine control of the U.S. House. At the center of this fight are the nation’s two states with the most members in Congress: Texas and California.

Republicans are plowing forward with plans for redistricting in several other states now that Texas is poised to approve its newly redrawn maps. The Lone Star State kicked off the redistricting arms race when Republicans in the state Legislature agreed to move forward with rewriting their congressional lines at the insistence of President Trump.