As Texas Republicans move ahead with redistricting to protect or even expand the GOP’s slim majority in the US House, Democratic-run states, led by California, are pushing forward with their own efforts to draw new maps and add Democratic seats.

Democratic National Committee Chair Ken Martin urged members of his party to forget their usual rulebook and go all in on partisan redistricting Tuesday.

The Supreme Court has ruled that judges are powerless to review partisan gerrymandering. But courts can still enforce the Voting Rights Act provisions that protect minorities' voting power.