A plague on both your houses: That’s pretty much what U.S. Senate candidate Rob Maness recommended when he recently called for his two major opponents — incumbent Mary Landrieu and U.S. Rep. Bill Cassidy — to stop airing false or misleading campaign commercials.

Maness, a retired Air Force colonel running as a tea-party Republican, referred to the harsh judgments of media fact-checkers when he cited one commercial each by Landrieu, a three-term Democrat, and Cassidy, a Baton Rouge physician who is her best-financed Republican challenger. But he needn’t have stopped there.

As a Democrat in a red state, Landrieu is near the top of the Republicans’ national hit list as they try to pick up the six seats they need in the fall elections for a Senate majority. The race has attracted lots of attention and heavy spending on political advertising. The Landrieu and Cassidy campaigns and various political organizations have been dinged repeatedly by fact-checkers for airing commercials that play fast and loose with the truth.

Maness has escaped the fact-checkers’ censure, which puts him in a good position to call out his two main opponents. He’s trailing both in the polls, and hopes to squeeze past at least one of them on election day, Nov. 4. If no candidate captures a majority of the vote that day, the top two finishers meet in a runoff Dec. 6.

Maness points to a Cassidy commercial in which Cassidy claims that Landrieu put illegal immigrants ahead of veterans in her votes on the federal budget. The issue involved some parliamentary back-and-forth around the bipartisan House-Senate budget deal last December to avoid a repeat of the October government shutdown, and specifically a provision to reduce cost-of-living increases for pensions of veterans who choose early retirement.

But Glenn Kessler, who writes the Fact Checker column for the Washington Post, said Cassidy’s claim is “ridiculous,” in part, because Landrieu never was confronted with a separate vote on the pension. She did vote for the overall package — but so did Cassidy, and he defended the pensions provision on a radio show. That led Kessler to penalize Cassidy for “hypocrisy,” and he awarded the commercial four long-nosed Pinocchios — his worst possible rating reserved for “whoppers.”

The cuts never went into effect; they were rescinded by legislation backed by both Landrieu and Cassidy.

The nonprofit, nonpartisan FactCheck.org, which is based at the University of Pennsylvania, also faulted Cassidy for that commercial, as did PolitiFact.com, a fact-checking division of the Tampa Bay Times (which gave the ad its worst rating, “pants on fire”). But as Maness noted in his double-barreled salvo, FactCheck criticized Landrieu, too, for a commercial in which FactCheck says she “quotes Cassidy out of context” to make the claim that he’s soft on securing the border.

That was part of the group’s review of immigration-focused ads, and FactCheck found plenty of blame to go around.

In her ad, Landrieu touts her support for a triple-layer border fence, which she did vote for in 2006 — only to call that vote a mistake in 2013. She also says she has voted nine times in the Senate to reject amnesty for illegal immigrants — referring to her support for legislation that Cassidy, in his ad, argues actually provides amnesty. “Both are wrong,” FactCheck says.

But the Cassidy-Landrieu-Maness contest is not the only election in the national spotlight this year, and Louisiana is not the only state generating dubious campaign advertising.

“It’s really a bad year for ads,” Kessler said. “Because the stakes are so high — control of the Senate — I think the advertising has really gone off the scales.”

Some of the worst offenders, Kessler said, are outside political groups, which don’t have to deal with the limits on contributions that apply to official candidate campaign committees — and that can spend freely, so long as they don’t coordinate their activities with the candidates. Millions have flowed into Louisiana already from those groups, on both sides.

Earlier this month, FactCheck.org gave a failing grade to an ad run by two pro-Democratic groups — Patriot Majority USA and the Senate Majority PAC — that accused Cassidy of voting to reduce veterans’ benefits. That vote, on a bill concerning inflationary adjustments in budgeting, would not necessarily result in cuts, FactCheck said.

And Senate Majority presented “audaciously false” claims about Cassidy in a commercial this spring, FactCheck said, by maintaining that he sponsored a bill for government-run health care when he was in the state Legislature and also advocated automatic enrollment of Americans in the Affordable Care Act. The same group drew fire from FactCheck with an earlier commercial linking the billionaire Koch brothers and their Americans for Prosperity advocacy group to Cassidy, suggesting he would advance the brothers’ agenda to let flood-insurance premiums skyrocket — when Cassidy worked actively with other members of the Louisiana delegation in Congress to rein in those premium increases.

That commercial on the Koch brothers registered a “mostly false” reading on the “truth-o-meter” of PolitiFact. A second Koch-Cassidy guilt-by-association commercial from Senate Majority, which claimed the brothers were out to protect tax breaks for companies that outsource jobs overseas, rated “false” on the truth-o-meter and four Pinocchios from Kessler.

But Americans for Prosperity hardly comes off as an innocent victim An ad the group ran in Louisiana early this year — featuring a woman bemoaning political ads — rang up a “false” on the PolitiFact meter for its claim that millions of Americans are paying more for health care and getting less in benefits under the Affordable Care Act; the act, known as Obamacare, is the signature legislation of Democratic President Barack Obama, and Republicans hope to capitalize this fall on dissatisfaction with Obamacare and with the president. AFP’s November attack on Landrieu as the “deciding vote” on ACA earned two Pinocchios from Kessler (“significant omissions and/or exaggerations”), while another Obamacare assault on Landrieu by AFP that month logged a “mostly false” from PolitiFact for claiming the law reduced full-time employment.

As for the candidates’ own campaigns, a Landrieu ad was branded “misleading” by FactCheck for the way it described Cassidy as hostile to Social Security, while Cassidy got two Pinocchios from Kessler for muddying the waters in a commercial on Obamacare exemptions for Congress. Cassidy received a “false” rating from PolitiFact for his ad claiming Landrieu and other Senate Democrats moved to finance long-delayed Veterans Affairs health clinics, including ones in Lafayette and Lake Charles, only after the VA scandal erupted this spring.

The campaigns and the outside groups who sponsor the advertising generally defend their claims when questioned by the fact-checkers: The explanations often are lengthy and convoluted. But ultimately, the fact-checkers make a call, and the frequency with which they bash both sides attests to their independence.

Beyond that, there’s little policing of political advertising. The TV stations that broadcast campaign commercials don’t play much of a role, according to Lee Meredith, the general manager for WAFB-TV Channel 9 in Baton Rouge.

“Broadcasters generally, including us, take a light touch,” he said.

Candidates and their official committees are largely free to say what they want, Meredith said. Outside groups are subject to more scrutiny, but it’s not an easy task, he said.

“It’s very difficult to parse the nuances of the claims,” he said.

Formal challenges to commercials are rare, Meredith said, but if one is filed, the station will ask the sponsor of the commercial for back-up information and will call in its lawyers to respond.

“Usually, by the time the lawyers and everybody has had their say, the ad is off the air anyway,” Meredith said.

Follow Gregory Roberts of The Advocate Washington bureau on Twitter, @GregRobertsDC