Kevin McCarthy, the leading candidate to take over the House leadership from outgoing Speaker John Boehner, is already drawing fire from Hillary Clinton's presidential campaign.

The Democratic front-runner on Tuesday released a 30-second commercial that highlights a controversial statement McCarthy made last week in an interview with Fox News' Sean Hannity.

"Everybody thought Hillary Clinton was unbeatable, right?" the House Majority Leader said. "But we put together a Benghazi special committee, a select committee. What are her (poll) numbers today?"

Clinton has attacked the statement ever since, arguing that McCarthy's comments show the Benghazi investigation has made "a partisan political issue out of the deaths of four Americans," Time noted. The former secretary of state is now driving home her point as part of her national cable TV ad buy.

"Republicans have spent millions attacking Hillary because she's fighting for everything they oppose, from affordable healthcare to equal pay," the first spot, titled "Admit," proclaims. "She'll never stop fighting for you and the Republicans know it."

The ad's content is significant as it marks the first time Clinton has used a commercial to hit back at Republicans over the select committee investigating the attacks on a U.S. consulate in Benghazi, Libya, on Sept. 11, 2012, the New York Times commented.

But Emily Schillinger, a spokeswoman for Boehner, told Fox News that the spot was an attempt to distract from the then-secretary's handling of the incident, as well as from the continuing controversy over the use of a private email server to conduct government business.

"This is a classic Clinton attempt to distract from her record of putting classified information at risk and jeopardizing our national security, all of which the FBI is investigating," Schillinger said.

McCarthy, for his part, insisted that he "never meant to imply" the committee's investigation was politically motivated. But Clinton said on Monday that she had been president, she would have done everything in her power to shut down the investigation, according to the news channel.

"This committee was set up, as they have admitted, for the purpose of making a partisan, political issue out of the deaths of four Americans," the Democrat insisted.