A conservative group is launching an ad attacking Sen. Mary LandrieuMary LandrieuMedicaid rollback looms for GOP senators in 2020 Five unanswered questions after Trump's upset victory Pavlich: O’Keefe a true journalist MORE (D-La.), one of the party's most vulnerable incumbents, for supporting Obama's judicial nominees.

The Judicial Crisis Network slams Landrieu in the ad for voting "for every one of Obama's liberal activist judges."

It also charges that, in voting to eliminate the filibuster for certain judicial nominees, she "helped change to rules to pack a key court with new liberal judges who will review … agencies Obama is using to push his unconstitutional job-killing agenda."

The ad is backed by a six-figure buy and will run statewide for two weeks.

It's the second attack of a vulnerable red-state Democrat from the JCI; Sen. Mark Pryor (R-Ark.) was the focus of its first ad, issued last month.