Republican legislators in California announced Wednesday that they are sending a letter to the U.S. Department of Justice and to the U.S. Attorneys representing California, calling for a potential federal investigation into who is behind the proposed new congressional maps in California and how they were constructed.

In a sign of Democrats' stiffening redistricting resolve, former President Barack Obama on Tuesday night backed Newsom's bid to redraw the California

The California Supreme Court on Wednesday rejected an attempt by Republican legislators to delay Democrats from gerrymandering the state’s congressional districts. The justices said the emergency petition, filed earlier this week, “failed to meet their burden of establishing a basis for relief at this time under” the California Constitution.

Newsom has called for a November special election to let voters decide on a new congressional map designed to flip up to five Republican-held seats.

California's Supreme Court rejected a Republican petition to halt legislative action on redistricting maps, potentially leading to a November vote. Re

The court said the petitioners “failed to meet their burden of establishing a basis for relief at this time” under the state’s constitution.

State legislators are scheduled to hold floor votes on Thursday, according to a schedule from Democratic leadership.