WASHINGTON, Oct 18 (Reuters) - A Super PAC backing Republican Donald Trump is buying TV airtime in parts of Florida beginning this week for a commercial aimed at using first lady Michelle Obama's words against Hillary Clinton to erode the Democratic presidential candidate's support from women voters in the battleground state.
The ad - which the Super PAC has already been running online - shows Michelle Obama in 2007 saying, "If you can't run your own house, you can't run the White House," which could be taken as a reference to infidelity by Clinton's husband, Bill Clinton.
The ad says Michelle Obama was talking about Hillary Clinton. However, at the time, then-candidate Barack Obama denied that his wife's words referred to his opponent for the Democratic presidential nomination.
Representatives for Clinton and Michelle Obama declined to comment on the commercial.
The Super PAC, Make America Number 1, is hoping the ad, to be aired in the Orlando and Tampa areas, will resonate with women, a spokesman, Hogan Gidley, told Reuters on Tuesday.
Trump has struggled for support from women voters, many of whom have cited his temperament and past negative comments about women, including comedian Rosie O'Donnell and Fox News host Megyn Kelly.
Eleven days ago, the New York businessman's campaign was shaken by the release of a tape showing Trump lewdly bragging about kissing and touching women without their permission. A series of women have since come forward with allegations about such behavior on his part, but he has denied the accusations.
In Florida, a Quinnipiac University poll released on Monday found Clinton leading among likely women voters, with support from 54 percent of those surveyed, compared with 39 percent for Trump.
Michelle Obama has become one of the most powerful campaigners for Clinton. A speech the first lady gave in New Hampshire last week attacking Trump for the tape was praised by many as one of the most powerful speeches of the campaign.
Make America Number 1 plans to spend $400,000 to put the ad on TV, spokesman Gidley said.
In addition to the TV run, the commercial initially appeared as a Facebook ad. The group spent $72,000 targeting women in nine key battleground states - states where the vote could swing to either candidate.
Super PACs - or super political action committees - are permitted to raise and spend unlimited amounts of money, but are prohibited by law from coordinating with a campaign. Make America Number 1 is one of a handful of such groups supporting Trump's White House bid.
Michelle Obama and Hillary Clinton have never directly addressed how they mended their relationship after the fierce 2008 primary campaign, in which Clinton lost to now-President Barack Obama. Both Obamas have campaigned aggressively for Clinton this year.
During last week's second presidential debate, Clinton called Michelle Obama "my friend."
Reporting by Ginger Gibson; Editing by Jonathan Oatis