Texas legislators on Wednesday passed a new state congressional map drawn at the behest of President Donald Trump to flip five Democratic-held US House seats in next year’s midterm elections, after dozens of Democratic lawmakers ended a two-week walkout that had temporarily blocked passage.

Republican legislators, who have dominated Texas politics for over two decades, have undertaken a rare mid-decade redistricting to help Trump improve their party’s odds of preserving its narrow US House of Representatives majority amid political headwinds. The map, which will have to be reconciled with the state Senate’s version, has triggered a national redistricting war, with governors of both parties threatening to initiate similar efforts in other states. Democratic California Governor Gavin Newsom is advancing an effort to redraw his state’s map to flip five Republican seats. Democratic-controlled California is the nation’s most populous state while Republican-led Texas is the second most populous. The Texas map would shift conservative voters into districts currently held by Democrats and combine some districts that Democrats hold.

Other Republican states — including Ohio, Florida, Indiana and Missouri — are moving forward with or considering their own redistricting efforts, as are Democratic states such as Maryland and Illinois.