WASHINGTON — A progressive group working to sink President Donald Trump's Supreme Court nominee is launching its first round of advertising Friday in three key states to pressure Democratic senators to vote against Brett Kavanaugh.

Demand Justice is spending a portion of its $5 million budget on the ads aimed at Sens. Heidi Heitkamp, D-N.D., Joe Manchin, D-W.V., and Joe Donnelly, D-Ind., and urging them to oppose Kavanaugh by warning that the nominee could rule to eliminate protections for pre-existing conditions.

The ads, obtained by NBC News, are complimentary of the Democratic senators' efforts to preserve the Affordable Care Act but caution that those actions could be nullified by the next high court justice.

“Thanks to Senator Donnelly more than 2.7 million Hoosiers with pre-existing conditions still have access to affordable health care. But those protections are at risk again, this time in the courts,” the narrator says in the Indiana version of the ad. “Kavanaugh refused to uphold key patient protections in the past, and if he joins the court he could vote to end these protections for good.”

Those three senators are primary targets of campaigns from both sides of the aisle as the confirmation process gears up because they represent states Trump won in 2016, are up for re-election in November and voted for Trump’s first Supreme Court nominee, Neil Gorsuch.

Democrats are honing in on the issue of health care as a key argument against Kavanaugh's nomination. The Supreme Court could hear a case in the next term challenging pre-existing conditions protections. And the subject is proving to be a top issue on the minds of voters heading into the midterms.

With only 49 votes in the Senate, Democrats have little ability to block the nominee from moving forward. If all Democrats vote against the nominee, one Republican would have to join with the Democrats for Kavanaugh to fail.

Demand Justice is already airing ads in Maine and Alaska, targeting Sens. Susan Collins, R-Maine, and Lisa Murkowski, R-Alaska, both senators who are pro-choice and voted to uphold Obamacare. Both have said they are keeping an open mind and will examine Kavanaugh’s record.