Nearly six years after defending the Affordable Care Act at the Supreme Court, former U.S. Solicitor General Don Verrilli is diving back into the fight to defend the Obama-era law.

Verrilli is among a team of lawyers representing the newly Democratic-controlled House of Representatives, which sought late Thursday to step in as a defendant in a lawsuit threatening to dismantle the ACA. Texas Attorney General Ken Paxton and several other states are leading that challenge.