“It's no secret that we preferred to start over” to repeal and replace Obamacare, he said. That vote failed in 2017. “So no, I don't fault the administration for trying to give us an opportunity to do this differently and to go in a different direction,” the majority leader said.

While Republicans sometimes have accused Democrats of turning to courts and executive actions when they were unable to get their way in Congress, McConnell said he didn't see an issue with backing the lawsuit.

'Nothing wrong'

“Nothing wrong with going to court. Americans do it all the time; we can do it too,” he said.

Vulnerable red-state Senate Democrats Joe Manchin of West Virginia and Claire McCaskill of Missouri have used the lawsuit as a cudgel against their Republican opponents — in each case the attorney general of their state — who signed on to the lawsuit.

A recent Manchin ad featured the senator shooting a copy of the lawsuit and accusing Attorney General Patrick Morrisey of wanting to “take away health care from people with pre-existing conditions; he is just dead wrong.” McCaskill has run a series of video testimonials featuring Missourians who depend on the health-care rules.

Other Democrats like Indiana Senator Joe Donnelly, Florida Senator Bill Nelson and Montana Senator Jon Tester are similarly using the GOP's support for the Texas lawsuit against their Republican rivals in competitive races.

Republican candidates argue that Obamacare isn't necessary to protect pre-existing health conditions, although they have yet to agree on an alternate plan to preserve those provisions. GOP-backed bills in the House and Senate would open the door to letting insurers charge higher rates to sick people or provide fewer benefits.

The clash comes down to a difference between Democrats and Republicans about what it means to cover pre-existing conditions. Democrats believe insurers should have to cover a minimum set of benefits without price discrimination based on medical history, while many Republicans want to relax those rules as a way to reduce premiums for healthier people.

Several Republican senators have criticized the Texas lawsuit, including Susan Collins of Maine, Lisa Murkowski of Alaska and Lamar Alexander of Tennessee, chairman of the health committee. Alexander backed legislation that would restore some protections for pre-existing conditions if the lawsuit is successful, but Collins declined to back it, saying it didn't go far enough to save provisions in the Affordable Care Act.

Catch up on the latest ACA developments:

• 9 ACA employer mandate FAQs
• Azar credits Trump with ACA lower premiums, disses Medicare for All
• Why the future of the ACA could be decided at the midterm elections

Copyright 2018 Bloomberg. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.