A weeklong walkout by Texas House Democrats is blocking redrawn congressional maps sought by President Donald Trump and put in motion a broadening fight across the U.S. over redistricting. There is still no swift end in sight to the standoff that has scattered dozens of Texas Democrats to Illinois,

Democrats concede there’s only so much they can do to keep Texas from redrawing its maps. But they want to encourage blue states to retaliate.

Democrats have left the state, the Republican governor and attorney general have vowed to remove them from office, and a senator has called in the F.B.I.