The latest challenge to the nation’s health care insurance program, the Affordable Care Act, goes before a Texas federal judge on Tuesday who is known for his past hostility toward the statute.

The case, Kelley v. Becerra, attacks a key leg of the statute—the guaranteed free preventive health services currently enjoyed by more than 150 million Americans. U.S. District Judge Reed O’Connor of the Northern District of Texas will hear arguments on motions for summary judgment by the challengers and the Biden administration. In 2018, O’Connor, in a separate challenge, struck down the entire statute as unconstitutional. The U.S. Supreme Court subsequently reversed.