Several partisan groups poured millions of dollars into West Virginia to put pressure on Conservative Democratic Senator Joe Manchin to discuss key items on his own party’s agenda.

The TV ad flash from both sides of the aisle started last month and lasted until June, according to data provided to CNBC by ad analytics firm Medium Buying. Two of the groups are virtually unknown and have been quietly trying to influence West Virginia over the past few weeks.

The advertising war comes as the conservative Koch network pressures Manchin to defy certain policies of its Democrats. It is also the latest example of the importance of the Manchin vote. The Democrats have a slim majority in the Senate with Vice President Kamala Harris tied, and Manchin is necessary for pretty much any bill the party wants to pass.

One group is End Citizens United / Let America Vote, an organization that works to end the big bucks in politics and improve voter access to the ballot box. Her publicity campaign calls for support for the For the People Act, the Democratic-backed electoral law that proponents say would limit the influence of big money donors.

The group began running digital ads in April and in television commercials in the state of Mountain in May. The paid media side of the campaign is expected to cost $ 2.5 million, according to the organizers.

CNBC checked a copy of a new ad the group will run this weekend in West Virginia. Although Manchin is not mentioned by name, it depicts Roger Champ, a veteran who was awarded the Purple Heart by the Senator in 2017. “We need the For the People Act. It’s time for tough ethics, ”says Champ in the ad.

Manchin recently wrote in a comment that he spoke out against the abolition of the filibuster and that he would not vote for the For the People Act, invoking his desire for more bipartisanism. However, his words did not prevent groups from addressing him.

“We’ve been around for months and will continue to do so as long as Manchin continues to say inaction is not an option,” Adam Bozzi, vice president of communications for End Citizens United / Let America Vote, told CNBC in an email.

Manchin officials did not respond to requests for comment.

A relatively new group, the West Virginia Freedom Alliance Action Fund, also wants Manchin to support the For the People Act. The group began serving ads in West Virginia in late May.

According to Medium Buying, the organization has spent more than $ 220,000 on both radio and cable television advertising since last month. Medium Buying’s latest ad on CNBC shows images of Manchin while a voiceover says, “Only a great senator can break the deadlock in Washington to diminish the power of big money, protect our suffrage and prevent politicians from doing so To draw elections. ” Cards that both a party and themselves benefit from. “

This group is represented by BlueWest Media, a Colorado-based media agency. Bernie Sanders’ 2020 presidential campaign paid BlueWest more than $ 20 million for “media advertising,” according to FEC records. BlueWest Media has not returned a request for comment.

Upholding Mountain Values, another group that has escaped media control, is calling on Manchin to oppose President Joe Biden’s $ 2 trillion infrastructure proposal. The organization has spent more than $ 100,000 on radio and cable television advertising since the beginning of this month, according to Medium Buying.

Medium Buying provided CNBC with a copy of Maintain Mountain Values’ latest ad. “Your so-called infrastructure plan? It’s a geyser of waste, billions for green energy, electric vehicles and more state welfare,” said a voice over during the ad. “Tell Joe Manchin to stop the radicals from pouring our tax money down the drain,” says the voice at the end of the ad.

Federal Communications Commission documents indicate that Maintaining Mountain Values ​​has hired SRCP Media as a media advisor. This advertiser lists the Swift Boat Veterans For Truth group, which targeted Democratic presidential candidate John Kerry in 2004, as one of their previous clients. Other clients listed include former GOP presidential candidate Mitt Romney and late Senate presidential campaign John McCain in 2000.

The treasurer of the FCC documents is Thomas Datwyler, who, according to his LinkedIn page, is a compliance advisor on campaign financing.

Data from the records of the Center for Responsive Politics and the Federal Electoral Commission list Datwyler as the campaign cashier for the failed congressional campaign of former Trump advisor and federal prisoner George Papadopoulos, who was pardoned by former President Donald Trump; a Super PAC sponsored by GOP Sen. Susan Collins of Maine; and other political organizations.

SRCP and Datwyler did not reply to any requests for comments by email.