Texas Lawsuit
After those efforts failed, the Justice Department backed the Texas lawsuit, which seeks to overturn the health-care law on constitutional grounds. The Trump administration, meanwhile, has taken regulatory action to expand the use of short-term insurance plans that don’t have to comply with pre-existing condition rules.

Hawley campaign spokeswoman Kelli Ford said he’s supporting the lawsuit because he views the ACA’s requirement that all individuals have health insurance as unconstitutional. She said Hawley "wants Congress to mandate that insurance companies cover everyone with pre-existing conditions" but didn’t say if he supports requiring a set of benefits to be included in policies.

In his own op-ed published last week, Hawley suggested requiring insurers to offer plans at the same prices regardless of whether the consumer has or had an illness, and have the federal government step in to help pay for costs above a threshold.

Shotgun Blast
GOP Senate candidate Patrick Morrisey, West Virginia’s attorney general, has signed onto the Texas lawsuit. Joe Manchin, the only Democrat to vote for Kavanaugh, has made that a centerpiece of his campaign. He’s run a TV ad in which he fires a shotgun at a copy of the lawsuit, saying Morrisey would "take away health care from people with pre-existing conditions; he is just dead wrong."

Donnelly and Montana’s Jon Tester, another Democrat running in a state where Trump won, are also trying to capitalize on the issue.

Representative Dana Rohrabacher, a 15-term Republican who represents Orange County in California and faces perhaps his toughest re-election battle, released an ad last week saying that he’s "taking on both parties and fighting for those with pre-existing conditions." Rohrabacher voted for his party’s Obamacare replacement bill that included state waivers from rules that prohibit charging higher prices to people with pre-existing conditions.

Trump has tried to counter by depicting himself as a champion for covering pre-existing conditions at recent rallies with Republican candidates, including Morrisey.

"I will always fight for and always protect patients with pre-existing conditions," he said on Sept. 29 in West Virginia.

Facing Attacks
Republican Senate candidates who have faced attacks from Democratic opponents on the issue include Senator Dean Heller of Nevada, Governor Rick Scott of Florida, Representative Jim Renacci of Ohio and Representative Kevin Cramer of North Dakota. All of them have supported their party’s efforts to unwind Obamacare.

Levitt and other health-care policy experts say that pre-existing condition rules are unsustainable without mechanisms to expand participation and provide financial assistance.