Voters across much of the South are casting ballots ahead of next month’s midterm elections under congressional maps redrawn after President Donald Trump urged states to redraw their districts. The changes are estimated to have given Republicans about eight more favorable seats than Democrats, but the outcome remains in voters’ hands. Republicans currently hold a 218-214 edge in the House. The new districts were drawn in part around how voters cast ballots in the 2024 presidential election. That calculation could prove risky: some Trump voters may now back Democrats or stay home, potentially putting districts Republicans targeted back in play. The redistricting push broke with the usual practice of revising congressional maps early in each decade, after the census. Trump’s call set off a chain reaction of legislative fights and legal disputes across the country, in a mid-decade redistricting wave described as exceptional in the modern era. The battle extended beyond Republican-led states. Democrats won statewide approval for new maps in California and Virginia in response to Republican efforts elsewhere, though courts later struck down Virginia’s plan. In other states, the process brought sharp clashes: Texas Republicans sought arrest warrants for Democratic lawmakers who left the state, Louisiana’s governor suspended a primary after voting had begun, and Missouri’s supreme court found the Republican secretary of state in contempt over use of a map that was not legally in effect. Some Republican lawmakers rejected Trump’s push, including legislators in Indiana and South Carolina. But across the country, the new boundaries have put control of the House partly in the hands of voters navigating districts that may look very different from those used in the last congressional election. The projected partisan advantage is no guarantee of seats if voter preferences have changed since 2024.