This week, academic and campaign finance reform activist Larry Lessig announced plans to spend $1 million on a Senate race in South Dakota, to boost the campaign of Democrat Rick Weiland. The investment will likely be met with some skepticism, coming so soon after a failed attempt by Lessig to help a little-known New Hampshire Senate candidate defeat Scott Brown in the GOP primary. And most Democrats have long written off this open seat — the forecasters view Weiland as an overwhelming underdog, and he hasn't led in a single poll:

But in an interview, Lessig argued to me that Weiland could win, and that his victory would help prove that voters care about reforming corruption in politics. "Our objective is to demonstrate something that people in Washington don't believe, which is that voters will vote on the basis of this issue," Lessig says. "To do that, you have to pick races that are difficult, where nobody expects you to win, but where based on our research we think we can win." Here's why he and other campaign finance reformers think South Dakota is one of those races.

1) Weiland's opposition to big money has been a major theme of his campaign



As you can see in the campaign ad / music video above, Weiland is running specifically on his opposition to "big money." The video portrays the smiling, happy Weiland singing (yes, singing) "no one's bought me," as he's haunted by the specter of a grim-faced, camera-wielding tracker from the conservative group America Rising. Beyond that, he's pledged that the first bill he'll introduce will be a constitutional amendment to let Congress regulate election spending more stringently.

"We've been watching Weiland since the beginning of the Mayday PAC," Lessig says, because of that message. But early on, that wasn't enough to win an endorsement — because Weiland didn't seem like he had a chance. Based on the public polling and research his own consultants conducted, Lessig says, "It was not clear it made sense to get into it earlier in the summer."

2) The GOP nominee has recently been tarnished by a scandal

In recent weeks, South Dakota headlines have been dominated by news about a scandal involving the administration of former Governor Mike Rounds — the GOP Senate nominee. The scandal, which has been simmering for some time, involves the state's administration of federal funds for the EB-5 program, which provides green cards for immigrants who invest $500,000 or more in rural or high unemployment areas.

The scandal's details are complex — here's a roundup of key stories from the Argus Leader's David Montgomery — but some Rounds appointees have been implicated in mismanaging contracts and funds involved in the privatization of the program, and one actually committed suicide shortly before he was to be indicted for embezzling half a million dollars.

"The conventional wisdom hasn't accounted for somebody spending twice as much as Rounds has in the bank"

Additionally, the very concept of EB-5 — giving green cards to immigrants who spend a lot of money in your area — sounds shady to many. Ann Lee of Demos has written that the federal program is "rife with fraud and corruption." One outside group of campaign finance reformers has even attempted to dub the scandal "The Mike Rounds citizenship-for-sale scheme," though that's a stretch.

Lessig argues that the nature of the scandal will help focus voter attention on his message. "The emergence of this EB-5 scandal has increasingly put pressure on Rounds in exactly the frame that we want this race to be thought of," Lessig says. "Which is, to what extent will we have a senator who will encourage cronyism and influence inside of our government, or to what extent will we have a senator who will stand up to that?"

3) Campaign finance reformers hope to double Rounds' spending

South Dakota is a small state where advertising is cheap, and outside groups can get a lot of bang for their buck. But Weiland hasn't raised very much money, so outside spending would help him a lot. Additionally, David Montgomery of the Argus Leader reported that Rounds has $1.1 million cash on hand for the final month of the campaign — which is not all that much for a competitive Senate race.

Now, Lessig's own group will pour in $1 million, combined with, he says, others who are spending another million. (That likely refers to another outside group of campaign finance reformers named Every Voice Action, which has been spending on the Weiland race for weeks, including on those anti-EB-5 ads.)

"The conventional wisdom hasn't accounted for somebody spending twice as much as Rounds has in the bank, on the basis of the one issue that Rounds is vulnerable on — cronyism," Lessig says. Of course, GOP outside groups could still try to come to Rounds' rescue if it looks like he's in deep trouble. But, Lessig says, his group could still up its commitment too — "We're spending at least a million," he emphasizes.

4) Other candidates could split the vote

Larry Pressler, a former three-term Republican senator from South Dakota, is also running for the seat this year, as an independent. He raised less than $10,000 in the first quarter of 2014. Yet in recent weeks, he's actually seemed to benefit the most in the polls from Rounds' decline — particularly in a shocking poll released Tuesday that put Rounds at only 35 percent of the vote, Pressler in second place at 32 percent, and Weiland at 28 percent. While Lessig prefers Weiland, he says, "Pressler is pretty good on these issues. So our campaign will be against Rounds and pro-Weiland, not against Pressler." (Pressler, 71 years old, has said he'll only serve one term, so he doesn't have to spend any time raising money. He hasn't said which party he'd caucus with.)

Weird things can happen in three-way races. Pressler could either make Weiland's victory possible, or doom it, depending on how much support he draws and whom he draws it from. In any case, the winning candidate in South Dakota will likely need only a relatively small plurality — particularly considering that another candidate, former GOP state senator Gordon Howie, is also running as an independent.

5) National Democrats have abandoned Weiland — so campaign finance reformers would get the credit for a win

Lessig's group doesn't want its spending to be just a drop in the bucket, on behalf of Democratic candidates who have more than enough money of their own to spend already. They'd prefer to look for potential upset opportunities that can win media coverage and help change the "conventional wisdom" that voters don't care about campaign finance.

South Dakota's race may provide a unique opportunity for this, because national Democrats and their outside groups have long written Weiland off — perhaps in part due to personal animosity from Harry Reid, whose close associates run several key outside spending groups.

Weiland is a former aide to Reid's predecessor as Senate Majority Leader, Tom Daschle (who himself held the other South Dakota Senate seat until his 2004 loss). Last year, when Reid was trying to woo his preferred candidates into the South Dakota race, Daschle encouraged Weiland to jump in himself. Reid was reportedly infuriated and openly said that Weiland was "not my choice." Earlier this year, Alexandra Jaffe of the Hill reported that Weiland was still getting the "cold shoulder" from DC Democrats.

Reid has long maintained that Weiland has no chance of winning, and Democratic outside spending groups — whether following his signals, or merely agreeing with his conclusions — have stayed out of the race. This provided the campaign finance reformers with a rather unique opportunity to jump in and be Weiland's main outside spending backers — though Wednesday afternoon, Bloomberg's Mark Halperin and Michael Bender reported that the DSCC would spend $1 million on the race after all.

"It won't be easy; there's no guarantee here," Lessig says. But he believes the potential payoff, if the upset actually happens, could be huge for the cause. Imagine if Democrats narrowly hold the Senate, due to a Lessig-funded shocker upset in South Dakota.

As in New Hampshire, Lessig's theory that he'll be able to pull off this unlikely victory remains, to put it mildly, untested. But many aspects of this race are strange — not least of which is the fact that campaign finance reformers are trying to overwhelm one candidate with outside spending. It will certainly be interesting to see what happens in South Dakota next.

Update: Added breaking news that the DSCC now plans to spend $1 million on the race.