The ad is the second of its kind from the incumbent Louisiana Democratic Senator.
Here's the text of the ad, approved by Landrieu and paid for by Democratic State Committee of Louisiana. The ad is airing on New Orleans' WYLD-FM radio station.
I'm Mary Landrieu, candidate for Senate, and I approve this message:
Man: News flash — Bobby Jindal endorses Bill Cassidy 100%. That troubles me. Jindal, our absentee governor, and Doc Cassidy, a medical doctor, oppose affordable healthcare for working families. These millionaire Republicans are against equal pay for women, and have opposed the Violence Against Women Act. And can you believe, Doc Cassidy has endorsed a documentary which claims slavery was better for black folks than welfare.
Woman: Oh no he didn't!
Man: Yeah, well he sure did, my friends. But worse than that, Cassidy and Jindal are trying to impeach our President. Back in the day, there was a TV cowboy named Hopalong Cassidy. I don't know if they're related, but why don't you just hop along, Doctor Cassidy, to wherever your number one supporter, Bobby Jindal, is headed this week, and let Senator Landrieu continue doing a great job for the people of Louisiana?
Cassidy/Jindal — bad for Louisiana, disastrous for black families.
Paid for by the Democratic State Central Committee of Louisiana.
The Landrieu campaign did not immediately respond to a request for comment. A Cassidy spokesman said he did not know what the ad was referring to.
Updated — Dec. 1, 7:53 p.m. ET
A Landrieu campaign aide pointed to Cassidy's appearance in a 2010 film A New America, which Cassidy called an "impressive video," as the source for the ad's claims.
In a scene taken from the movie and posted on YouTube, Star Parker an African-American Republican and founder of the Coalition for Urban Renewal and Economic Development draws comparisons between welfare and slavery but doesn't make the claim that "slavery was better for folks than welfare," as the ad says.