Kentucky Democrat Alison Lundergan Grimes went on the attack against Sen. Mitch McConnellMitch McConnellDems engage in friendly debate for DNC chair Senate seeks deal on Trump nominees Overnight Finance: Smooth path for Commerce pick after hearing | Treasury nominee to defend foreclosure record | GOP tax turmoil MORE (R-Ky.) in a new ad Friday that targets the senator for increasing his own wealth while voting for harmful economic policies.

"What can happen in 30 years?" a narrator asks in the ad, which launched in Kentucky last Thursday. "A senator can become a multi-millionaire in public office while voting 17 times against raising the minimum wage, three times for corporate tax breaks that send Kentucky jobs overseas and 12 times against extending unemployment benefits for laid-off workers."

The narrator adds: "And when asked about it, just laughs. Thirty years of Mitch McConnell is long enough."

The attack marks a break in tone for Grimes from the series of humorous ads she’s launched over the past month, which have featured her and a local Kentuckian asking questions of McConnell intended to highlight his record on issues like fair pay and job creation.

It comes as a handful of polls released in previous weeks show McConnell opening up a slight lead on the Democrat after the two have begun ramping up for the general election fight.

But McConnell’s campaign hit back, calling the ad an attack on his wife, former U.S. Labor Secretary Elaine Chao, because it targets the senator for his personal wealth, a large portion of which was inherited from Chao’s father in 2007. McConnell has also earned at least $4 million in salaries from the government since 1985, according to records supporting the ad’s claims.

"The latest attack ad from Alison Lundergan Grimes is nothing short of despicable," McConnell spokeswoman Allison Moore said in a statement. "Apparently, Grimes' entire candidacy has been reduced to attacking Mitch McConnell's wife at every turn in the hopes she can distract Kentuckians from her profound inexperience and steadfast commitment to the Obama agenda."

Chao has become a central figure and defender in McConnell’s campaign as he competes with Grimes for female voters in a race that's one of Democrats' few pick-up opportunities this cycle, due in part to McConnell's personal unpopularity.

Last week, she starred in an ad defending her husband’s record on women’s issues, but also offered fodder for Democratic attacks when a Yahoo News report revealed she served on the board of a group that spent tens of millions to close coal-fired power plants.