Americans for Prosperity, a well-funded conservative group backed by the Koch brothers, is launching a major ad campaign attacking two vulnerable Senate Democrats on ObamaCare.

The $2 million campaign will target Sens. Kay HaganKay Hagan Former Sen. Kay Hagan in ICU after being rushed to hospital GOP senator floats retiring over gridlock 2016’s battle for the Senate: A shifting map MORE (D-N.C.) and Mary LandrieuMary LandrieuFive unanswered questions after Trump's upset victory Pavlich: O’Keefe a true journalist Trump’s implosion could cost GOP in Louisiana Senate race MORE (D-La.) with three weeks of television ads focused on the controversial law.

Americans for Prosperity has been on the air for months seeking to frame ObamaCare as a disaster that threatens individuals' healthcare plans. These ads represent a shift from attacking aspects of the law to focusing on those who support the law and are facing reelection — and follow on the heels of ads in four swing House districts on the same topic.

"So far the ObamaCare rollout has been a perfect demonstration of inept big government. The actual impact of the law has been dwindling choices, rising premiums, and millions of Americans losing the plans they were told they could keep," AFP spokesman Levi Russell said. "Politicians like Hagan and Landrieu's response has been to double down on this disaster, while making sure political allies and members of Congress get special treatment under the law. Our job is to hold them accountable for that.”

Both Hagan and Landrieu are top GOP targets — Republicans need to defeat one, and possible both, of them if they hope to win Senate control next year.