In a TV ad from Democrat Dean Phillips, an actor in a rather convincing Bigfoot costume talks about searching for Republican Rep. Erik Paulsen, whom Democrats criticize as invisible to his constituents. In another, a Republican group allied with Paulsen bashes Phillips for his wealth and his background in the liquor business.

Flip the channel: There’s Rep. Jason Lewis, another Republican, promising to be an “independent voice” for Minnesota. His opponent, Democrat Angie Craig, talks about growing up without health care.

On it goes, day after day and night after night, a back-to-back barrage of spirited pleas and scorching attacks that won’t let up for six more weeks. During a single break in one local TV news broadcast last week, spots by candidates and their allies accounted for 17 of the 23 total commercials that aired during the program. Millions of dollars are being spent on ads in this battleground state this year, especially in a handful of fierce contests for Congress.

The ads are a constant reminder of the extremely high political stakes in Minnesota’s congressional contests in this midterm election. With two Republican incumbents fighting to hold on in the Twin Cities suburbs, and Democrats defending two more rural districts carried in 2016 by President Donald Trump, the national battle for control of Congress runs right through the state. Candidates for governor and U.S. Senate are also airing plenty of TV ads. Live TV viewers trying to tune out politics are collateral damage.

“The candidates don’t want the airwaves to be left to the other candidate,” said Benjamin Toff, an assistant professor at the University of Minnesota’s Hubbard School of Journalism and Mass Communication. “There’s kind of an arms race.”

According to Kantar Media/CMAG, which tracks TV ads nationwide, Minnesota ranks in the top 10 states for TV ad spending so far this election season, with a majority of the money being spent on House races.

The biggest ad spending is in the Third District, where Paulsen faces a tough challenge from Phillips in the southwestern Twin Cities suburbs.

That’s followed by the Second District, mostly southeastern suburbs where Craig is running against Lewis.

A recent analysis of ad spending by the Wesleyan Media Project found the Third District tied for third nationwide for the highest ad spending in the period of Sept. 4-17, with $1.1 million spent and 2,338 ads aired. Only a district in Colorado and one in Pennsylvania saw higher spending.

Occasionally, a political ad breaks out big. Phillips recently drew national attention for his “Bigfoot” ad, adopting a mockumentary style to interview Bigfoot about his search for Paulsen, echoing attacks by Phillips’ campaign that Paulsen isn’t accessible enough to voters.

Initially a digital-only spot, it’s now been viewed on social media sites more than 1 million times, was mentioned by Ad Week and Forbes, and helped the campaign fundraise enough to run the ad on TV last Thursday night during the Vikings pregame show.

“We didn’t expect it to go viral,” said Richard Carlbom, Phillips’ campaign spokesman. “It’s not a traditional political ad.”

Meanwhile, Paulsen’s campaign and Republican groups have targeted Phillips’ business background in TV ads. One focus has been the coffee shop he opened several years ago, which did not initially offer health insurance to employees.

“We’re searching for something far more elusive: Dean Phillips telling the truth,” Paulsen campaign manager John-Paul Yates said. As to Bigfoot’s accusation that he’s inaccessible, Paulsen did hold town hall meetings last spring for the first time in years, and has said he prefers a more low-key style such as open office hours, private meetings and telephone town halls.

In the Second District, Lewis and allies are also singling out Craig, a former health care executive, for her business background.

The National Republican Congressional Committee (NRCC) dropped another spot on Tuesday.

A previous NRCC ad on the same subject generated controversy by accusing Craig of making “millions in ill-gotten gains.” The Craig campaign asked local broadcasting stations to take the ads down over concerns they were false and misleading. But the ad was suspended only briefly.

The ad says Craig’s companies have a long history of lawsuits. But Craig didn’t own the multinational medical technology corporations the ad was referring to, Smith & Nephew and St. Jude Medical. She was a high-ranking employee.

“A number of independent journalists have highlighted the ad’s dishonesty ... and we trust that people will recognize the ad for what it is,” the Craig campaign said in a statement.

Issue-based political action committees are also getting in on the ad game. The Environmental Defense Action Fund launched another $1 million ad campaign across four House races, including against Lewis, last week.

Two gun safety groups — Giffords and Everytown for Gun Safety — have launched ads respectively hitting Lewis and Paulsen.

“Isn’t it ironic that Angie Craig and her Democrat cronies are casting judgment on Jason Lewis for ‘taking money from special interests’ while groups like Giffords PAC and Environmental Defense Fund Action are throwing more than a million dollars at Angie Craig to support their special interests?” said Becky Alery, a spokeswoman for the Lewis campaign, in an e-mail.

While a bulk of the TV ads are focused on the two suburban Twin Cities races, the saturated TV market is also getting blasted by ads for the First and Eighth districts, the Trump districts where two Democratic incumbents are not running again.

In southern Minnesota’s First District, there was an exchange of fire over ads between Republican Jim Hagedorn and Democrat Dan Feehan. The NRCC released an ad slamming Feehan, a two-time Iraq veteran and former Pentagon official, saying he “supports giving up to $150 billion to Iran — a regime that funds terrorism,” while resisting funding increases for the U.S. military.

VoteVets, which supports veteran candidates, responded with an ad defending Feehan. It said Hagedorn’s health care proposals would force 340,000 veterans — 17,000 of them in Minnesota — to lose their coverage. “That’s a disgrace,” the ad said, calling Hagedorn “not fit to serve in Congress.”

In the battleground Eighth District, which covers a wide swath of northeastern Minnesota, outside groups have doused voters with ads. A conservative super PAC is hitting Democratic candidate Joe Radinovich for traffic citations and having fines referred to collection agencies. Their Democratic counterpart is airing ads calling Republican Pete Stauber a “typical politician” who supports tax breaks for special interest groups.

The campaigns, meanwhile, have taken a positive tack with recently released ads focusing on taking care of family, friends and Minnesotans. Stauber’s wife, Jodi, narrates a new ad about how he cared for their children when she was deployed with the Minnesota Air National Guard. Radinovich’s latest ad features him and Richard, a man he has mentored for years, going hunting.

For the Second District, Craig launched an ad Tuesday about health care, talking about her own family’s lack of insurance when she was young.

And in the Third District, Paulsen’s first ad was largely biographical, showing him paddling a canoe and discussing the Boundary Waters.

While Minnesotans may gripe at being inundated by political ads, research shows ads do help sway a small segment of voters, help with name recognition and inform voters about policy debates, Toff said. With more outside groups — which tend to run negative ads — spending money on ads this year, Minnesotans are seeing more of them. Even those negative ads, research shows, inform voters — though sometimes with inaccurate details.

“It’s important to be aware,” Toff said of the impact ads play on voters. “It puts a lot on individual voters to sort through all that.”

Staff writers Judy Keen and Jessie Van Berkel contributed to this report.