Updated 3:15 p.m. | In a possible preview of Senate Democrats’ midterm political messaging, Democratic senators want the chamber to go to court to defend health insurance protections for people with pre-existing conditions.

Two of the Democrats leading the effort face Republican challengers in 2018 who have signed on to the legal effort that could undermine the regulations from the 2010 health care law: state attorneys general in Missouri, Josh Hawley, and West Virginia, Patrick Morrisey.

“We’re asking all of our colleagues, and our friends on the Republican side of the aisle to join with us … to stand up against this horrible, horrible position that the attorneys general offices in my state and Claire’s state, but also the Department of Justice,” West Virginia Democratic Sen. Joe Manchin III said Thursday.

Manchin and Sen. Claire McCaskill, D-Mo., are among those leading the introduction of a Senate resolution that would authorize the Senate to take legal action to intervene in litigation led by Texas that could undercut the protections on the health insurance exchanges and in the broader market.

Morrisey and Hawley have signed on to the lawsuit, so it is no surprise that the Democratic Senate incumbents they’re challenging in 2018 would take the lead on the new legislative effort.

They were joined Thursday morning by fellow Democratic Sens. Bob Casey of Pennsylvania and Patty Murray of Washington, along with Minority Leader Charles E. Schumer of New York.

The effort has the backing of the outside group Protect Our Care, which has been leading the effort to stop efforts to roll back the 2010 health care overhaul law.

“If Republicans in Congress won’t endorse this resolution, they will once again make clear they’re on the side of insurance companies, not Americans who work for a living,” Brad Woodhouse, the executive director, said in a statement. “Thank goodness Democrats will not stop fighting for the protections that prevent insurance companies from jacking up premiums for people with pre-existing conditions — or denying us care altogether — because if Democrats stopped fighting, these protections would be long gone by now.”

Democrats have viewed the debate over pre-existing condition protections as among the issues most likely to resonate with voters in their favor in November, even in states carried comfortably by President Donald Trump, like Missouri and West Virginia.

The Morrisey campaign responded by framing Manchin’s work on the resolution as opposition to Trump.

“Sen. Joe Manchin continues to put the interest of Washington liberals like Chuck Schumer and his radical special-interest donors ahead of the health care of West Virginians,” Morrisey campaign spokesperson Nathan Brand said in a statement.

Hawley said in a previous statement provided to Roll Call that he supported the pre-existing condition protections, as well as allowing young people to stay on their parents’ insurance plans to age 26.