Florida Sen. Bill Nelson and a cadre of Democrats are taking steps to protect the healthcare coverage of millions of Americans with preexisting conditions.

Nelson et al filed a resolution Thursday authorizing the Senate Legal Counsel to take up defense of a federal lawsuit, Texas v. United States, which would undo protections for those with preexisting conditions.

The move comes a month after the Department of Justice declined to defend the nation's healthcare law against the suit, filed by attorneys general of 20 states.

"We should be working together to lower the cost of health care,” Nelson said. “Instead, the state of Florida is using the federal courts to take the guarantee of health insurance away from millions of people with pre-existing conditions – including 7.8 million Floridians.”

Nelson headlined a letter to Gov. Rick Scott, also his opponent in the upcoming midterms, last month, imploring him to remove Florida from the lawsuit.

"By joining this lawsuit, the state of Florida is actively working to hurt Americans with preexisting conditions," Nelson and the 11 other Florida lawmakers wrote.

"Having failed multiple times to rip health coverage away through Congress, the Trump administration is now attempting to use the court system to take the guarantee of health coverage away from 7.8 million Floridians with preexisting conditions. This is wrong," they wrote.