The kickoff ad repeats a clip of McConnell saying "I've lived on a government salary for 30 years" as the screen flashes details on his record, noting his votes to raise congressional pay, for the financial bailout and for cuts to Medicare.
"Mitch McConnellMitch McConnellTrump flirts with Dems for Cabinet Lawmakers eye early exit from Washington Confirm Scott Palk for the Western District of Oklahoma MORE 'has long ceased to serve the state,'" the video reads, a quote from a blistering Courier-Journal editorial.
"After 30 years … it's time to switch."
It will be backed by a minimum $250,000 buy and will run statewide in Kentucky.
Senate Majority PAC's choice to make McConnell one of its first targets this cycle — it's spent heavily in the Massachusetts Senate race, but hadn't yet launched air attacks on incumbent Republicans — reflects the belief among Democrats that McConnell's one of the most vulnerable Republicans heading for reelection this cycle.
The groups cite Democratic polling that has shown McConnell to be one of the most unpopular Senators in the nation, and vulnerable to a potential Democratic opponent.
McConnell is aware of the target on his back, however — he's already gone on air with ads of his own, featuring his wife criticizing attacks from a progressive group, and he's been working to build his image as a fighter for Kentucky.
McConnell campaign manager Jesse Benton tied the new ad to previous attacks from Democratic groups and said the heavy Democratic offense may actually be improving McConnell's support.
""From office buggings, to racist tweets about Mitch's wife, to the constant stream of negative ads, Barack ObamaBarack ObamaFor Trump, foreign policy should begin and end with China Harvard spat between Clinton, Trump camps proves Dems can't accept Trump's improving Wrestling mogul McMahon could slam her way into Trump administration MORE's allies are desperate to attack Senator McConnell at all costs," he said. "The increasingly unhinged attacks by Washington liberals only reaffirm Kentuckians' pride in Mitch McConnell for fighting to protect Kentucky from Obama's bad ideas."
National Republican Senatorial Committee spokesman Brad Dayspring suggested that Senate Majority PAC would frustrate incumbent red-state Democrats by spending on McConnell, which he said is akin to "lighting their resources on fire."
"Endangered red-state Democratic Senators like Mark PryorMark PryorCotton pitches anti-Democrat message to SC delegation Ex-Sen. Kay Hagan joins lobby firm Top Democrats are no advocates for DC statehood MORE, Mark BegichMark BegichThe future of the Arctic 2016’s battle for the Senate: A shifting map Trump campaign left out of Alaska voter guide MORE, and Kay HaganKay HaganGOP senator floats retiring over gridlock 2016’s battle for the Senate: A shifting map The untold stories of the 2016 battle for the Senate MORE must be thrilled that Harry ReidHarry ReidDemocrats local party problem Trump flirts with Dems for Cabinet Lawmakers eye early exit from Washington MORE's super-PAC is lighting their resources on fire in Kentucky rather than helping them to protect their seats from being lost," he said.
He also noted that Democrats have been unable to convince their top remaining recruit, Kentucky Secretary of State Alison Lundergan Grimes, to jump in the race.
"Though may be the most reluctant candidate in America, nonetheless Democrats are desperate to find a sacrificial lamb in Kentucky and if they want to burn their resources in the process that's just fine with us," he said.
--This piece was updated at 12:14 p.m. to clarify polling on McConnell's popularity.