A powerful, deep-pocketed force in California politics endorsed redrawing the state's congressional maps to counter President Trump's effort to push GOP states, notably Texas, to increase his party's numbers in Congress in next year's midterm election.

As a Texas senator summoned the F.B.I. to round up Democrats, the redistricting war that began in Texas was spreading, with California aiming at five Republican House seats.

Texas Republicans have launched efforts to redraw congressional maps to secure more GOP seats in the U.S. House