In little New Hampshire’s big money U.S. Senate primary, Republican Jim Rubens should be an afterthought at best.

This former New Hampshire state senator, after all, hasn’t occupied elected office since the late 1990s. He then lost a bid for governor, and failed to win back his old state Senate seat in 2000. But when a quixotic, out-of-state super PAC with a million-plus dollars to burn suddenly backs you, the atmospherics change. “I would not have a chance without the super PAC,” Rubens acknowledged. “Now I do.”

Mayday PAC is, paradoxically, an anti-super-PAC super PAC that pumps serious cash into campaigns of candidates like Rubens who'd like to see super PACs disappear altogether. Prior to Mayday PAC’s involvement, a poll by the University of New Hampshire Survey Center and television station WMUR-TV indicated four in five voters statewide had no opinion of Rubens, one way or another. “This is exactly why we’re in there—to effect change and change how he’s doing,” said Larry Lessig, the Harvard Law School professor who founded Mayday PAC: “We’re optimistic we’re going to be effective.”

To be sure, a Rubens victory today would be outrageous, even for a state known for its rebellious streak—voters memorably picked commentator Pat Buchanan over standard-bearing Sen. Bob Dole during the 1996 Republican presidential primary—during a year when a GOP luminary like House Majority Leader Eric Cantor fell in a primary to a little-known challenger. Scott Brown, the former senator from Massachusetts who lost his seat in 2012, is expected to win the New Hampshire's GOP primary.

Funded by thousands of small-dollar donations, Mayday PAC’s more than $1.6 million investment in Rubens ahead of Tuesday’s primary nevertheless illustrates how a lone special interest group can scramble a critical Senate race in the post–Citizens United v. Federal Election Commission era of increasingly deregulated political money and campaign finance exotica, like “dark money” committees and “mommy PACs.” And it’s distracting Brown from a full, general election pivot toward Sen. Jeanne Shaheen, the moneyed Democratic incumbent. That’s hardly ideal for Republicans desperate for a New Hampshire victory in their bid to pick up six seats nationwide and control a Senate majority.

In fact, Brown campaign manager Colin Reed this weekend fired a cease-and-desist letter to Lessig, accusing his super PAC of, among other misdeeds, “hypocrisy,” “falsehoods,” violating Harvard University’s honor code, and propagating the “flat-out lie” that Brown was a lobbyist. It promised to leave “all our legal options on the table.”

In response, Lessig wrote on his blog, in quoting Dirty Harry: “Go ahead. Make my day.”

Brown campaign spokeswoman Elizabeth Guyton declined to comment, instead referring to a campaign press release that focuses on Shaheen, in part criticizing her for running a campaign of “tightly-controlled events with limited interactions with the media or members of the public” and relying on “outside, third-party groups” to buoy her candidacy.

No matter for Democratic interest groups, which are reveling in the Republicans’ intramural scrap and using it to sling millions of dollars worth of negative ads at Brown, even before the general election officially begins. Shaheen, although generally popular in a state that’s both elected her governor and senator, is nonetheless dogged by President Barack Obama’s unpopularity, and her backers are using all the time they have to buttress her re-election bid.

Two groups have each already spent more than $1 million attacking Brown: liberal super PAC Senate Majority PAC and NextGen Climate Action Committee, a super PAC run by billionaire environmental activist Tom Steyer. The League of Conservation Voters’ election arm has spent almost $400,000 to do the same. And the Democratic Senatorial Campaign Committee just launched a multimillion-dollar ad blitz blasting Brown’s record during his brief U.S. Senate stint. Such spending is part of nearly $6.5 million worth of overt candidate advocacy by political committees and nonprofits in New Hampshire’s Senate race.

Almost all of the organizations spending money—including the pro-Brown U.S. Chamber of Commerce and super PAC Ending Spending Action Fund, formed by TD Ameritrade founder Joe Ricketts—are based in states other than New Hampshire. Mayday PAC is headquartered in Austin, Texas.

Shaheen’s campaign itself, at last count Aug. 20, had nearly four times more cash on hand than Brown’s campaign, $4.27 million to $1.19 million, according to Federal Election Commission filings. “If Brown doesn’t come out of the primary with a fairly resounding victory, that doesn’t look good for him going forward,” said Norma Love, who recently retired as the Associated Press’ New Hampshire political reporter after more than three decades. “There’s a lot at stake for him Tuesday.”

For voters in this state of about 1.32 million people—only eight U.S. states have a smaller population—the Senate spending spree translates into a deluge of messaging that rivals presidential election season, when New Hampshire hosts first-in-the-nation party primaries.

Statewide, New Hampshire has but a single, network-affiliated television station in WMUR-TV. No matter: Granite Staters have seen nearly 4,500 U.S. Senate-related ads this election cycle through Aug. 25, according to a Center for Public Integrity analysis of data compiled by Kantar Media/CMAG, an ad tracking service. That number figures to be hundreds, if not thousands more by the time residents take to the polls Tuesday, particularly since pro-Rubens Mayday PAC has run all of its ads during the Republican primary’s final days.

News programs, perhaps not surprisingly, are the most popular advertising platforms among most large political groups, as well as the Brown and Shaheen campaigns.

After that, light entertainment rules: Candidates and noncandidate groups have combined to air 179 ads on game show Who Wants to Be a Millionaire. That includes 24 from Senate Majority PAC, a super PAC that supports Democrats, and 23 from Koch brothers-backed Americans for Prosperity, which names candidates in the race but doesn’t directly advocate for or against them—a practice that allows it to avoid disclosing its ad spending to the FEC. Americans for Prosperity may also use “dark money” to fuel its ads, since as a nonprofit, it isn’t legally compelled to reveal its donors.

Morning gabfest Live! With Kelly and Michael has attracted 175 ads in New Hampshire’s Senate race, Jimmy Kimmel Live 149, and the Ellen DeGeneres Show 138. Ellen, it turns out, is an Americans for Prosperity favorite, with the group so far running 40 ads during the daytime gabfest—more than the Shaheen or Brown campaign or any other noncandidate group.

New Hampshire’s Senate race, with all its spending, could have been wildly different. It’s a massive departure from 2012 re-election bid in Massachusetts, when Brown cast himself as a novel kind of campaign finance reformer. He signed a “people’s pledge” pact with Democratic opponent Elizabeth Warren with the goal—largely successful—of shooing noncandidate groups from the race.

No such pledge materialized between Brown and Shaheen, despite Shaheen’s call in March for him to sign one commensurate with his 2012 pledge. Brown called Shaheen’s ask “self-serving,” noting she was off on a fundraising trip in California. And national Republicans argued that liberal outside groups had already spent significant money in New Hampshire before Brown even declared his candidacy.

The lack of a “people’s pledge,” curiously, allowed campaign finance reform-touting Mayday PAC to become Rubens’ political lifeline—however tenuous—and make political money one of the race’s focal points alongside health care, taxes, jobs, and the economy. But the campaign’s big-money turn isn’t a boon for all candidates. Ask former U.S. Sen. Bob Smith, who’s also competing in Tuesday’s GOP primary.

Despite serving New Hampshire in Congress for nearly two decades, including two terms in the U.S. Senate, his latest political comeback—he ran for U.S. Senate in Florida during 2004 and 2010—has floundered, his campaign cash starved and seemingly chaotic. It’s certainly a mere shadow of the professionalized outfit backing him in 2002, when he lost his seat in a Republican primary to eventual Sen. John E. Sununu.

For example, after Smith’s campaign chided media outlets last week for ignoring a concert event it hosted—“the media was missed,” said media adviser Di Lothrop—Smith and his campaign refused over several subsequent days to comment about the race.

Super PACs and nonprofits are largely shunning Smith, too. Only a pair of Tea Party–aligned groups have combined to spend less than $29,000 to directly back the former lawmaker, doing so with online ads and some supportive phone calls. Compare that to Senate races in Kentucky and Mississippi, for example, where Tea Party groups shoveled millions into the ultimately losing primary bids by very conservative candidates.

The manner in which politics is waged, even in a state like New Hampshire where voters put a premium on retail politicking, appears to have passed Smith by. “This is the first Senate race ever where we’ve seen a significant amount of super PAC money, ‘dark money,’ all of the above,” said Dante Scala, a University of New Hampshire political science professor. “This is how it works now.”

As far as Rubens is concerned, there’s nothing wrong with using this system to point out the flaws in it.

“I appreciate the super PAC support,” he said. “It helps be show that this country’s problems won’t be solved until we replace our corrupted political money system.”

This story was published by the Center for Public Integrity, a nonprofit, nonpartisan investigative news organization in Washington, D.C.