An oft-maligned Washington trade is under attack, again.

On television screens across Montana and Wisconsin, the Democratic Senatorial Campaign Committee this month is showing two ads that put the spotlight on lobbying, a favorite punching bag of voters of both political parties. The spots turn up the heat on a couple of Republicans who are running for U.S. Senate and have ties to lobbyists.

The ad put out by the DSCC on September 12 takes aim at the seven-year stint former Wisconsin Governor Tommy Thompson (R) spent at Akin Gump Strauss Hauer & Feld in D.C. The other spot, which went out on September 17, targets Rep­resentative Denny Rehberg (R-Mont.) for remarks he made last year in support of lobbying at a gathering sponsored by the American League of Lobbyists, an industry trade group.

DSCC spokesman Matt Canter declined to comment on the spots, saying: “I’ll let the ads speak for themselves.”

Howard Marlowe, president of the American League of Lobbyists, had more to say. On September 19, he fired off a letter to Senator Patty Murray (D-Wash.), chairwoman of the DSCC, expressing concern with the group’s ads. “ALL does not involve itself in any partisan or political matters,” he wrote. “Therefore, it is of serious concern that the DSCC is using the current election campaigns to attack our profession.”

Canter also declined to comment on the letter.

Anti-lobbyist campaign ads aren’t new, and they come from both parties. Senator John McCain (R-Ariz.) and former President Bill Clinton have released them before. And President Barack Obama has put them out, too.

Obama signed an executive order aimed at lobbyists in one of his first actions as president. Among other restrictions, the directive limits the work executive branch officials can do on matters that involve their former employers or clients.

Despite Obama’s attacks, it’s worth noting that the White House has doled out 13 waivers for administration officials who previously worked as lobbyists. The list includes former Deputy Defense Secretary William Lynn III, a one-time top lobbyist at defense contractor Raytheon Co., and White House Domestic Policy Council director Cecilia Muñoz, who lobbied for the National Council of La Raza, a Latino civil rights organization.

In the DSCC’s 34-second Thompson ad, shadowy figures move around in offices and shake hands as a male narrator discusses Thompson’s work for “special interests” at Akin Gump. Thompson came to the firm in 2005, after he stepped down as U.S. secretary of Health and Human Services.

“Thompson sold his influence and connections, becoming a partner in a powerful Washington lobbying firm,” the narrator says.

Akin Gump spokesman Benjamin Harris declined to comment on the ad. But a Thompson campaign spokeswoman said the campaign isn’t threatened by the ad or Representative Tammy Baldwin (D-Wis.), who is running against the former governor for the seat held by retiring Democratic Senator Herb Kohl. “The DSCC’s ad reeks of desperation,” Thompson campaign spokeswoman Lisa Boothe said in a written statement.

Thompson wasn’t exactly a lobbyist, according to lobbying registration records filed with Congress. But Thompson, a lawyer, advised Akin Gump health care clients that included the Pharmaceutical Research and Manufacturers of America, Novavax Inc. and PharmAthene Inc., according to a financial statement he provided to the Milwaukee Journal Sentinel in January. From January 2010 to October 2011, he made $771,000 at the firm.

According to the nonpartisan Center for Responsive Politics, Akin Gump employees have donated $25,000 to Thompson’s campaign. The sum is the fourth-highest amount employees of a single organization have raised for Thompson. Using data from the center, it wasn’t immediately clear what — if any — campaign donations Baldwin received from Akin Gump employees. If any Akin employees did contribute to her campaign, according to the center, the amount would have totaled less than $10,000.

The DSCC’s 32-second Rehberg spot features audio of the congressman’s comments at an October 14, 2011, American League of Lobbyists event. In the audio used for the ad, Rehberg calls lobbying “an honorable profession” and tells lobbyists that he has to “rely on you guys to tell me the information.” While the audio plays, a grayscale photo of Rehberg appears on the screen with the text of the quotes.

“He’s not for you,” a male narrator says.

Chris Bond, a Rehberg campaign spokesman, said the ad is ironic because of the donations lobbyists have made to Senator Jon Tester (D-Mont.), Rehberg’s opponent. According to the Center for Responsive Politics, Tester has received $421,131 from lobbyists — the most money they’ve collectively given to any Senate candidate during this election cycle. Rehberg has taken in $166,883, which puts him at No. 17.

“Montanans aren’t going to be swayed by these hypocritical attacks from Tester’s liberal Washington allies,” Bond said in a written statement.

Marlowe said the release of the audio from the off-the-record talk “really upset us significantly.” He said the incident has put gatherings the group has with members of Congress in jeopardy.

“It’s always been a great opportunity,” Marlowe said of the events.

Andrew Ramonas can be contacted at aramonas@alm.com.