The full Vermont House is set to debate restricting Super PAC donors to $5,000 donations per election cycle, with attorneys, lawmakers and party officials scrambling to stake out strong positions.

The chief controversy involves a likely lawsuit the state could face if it enacts such a cap. If passed by the House, the legislation must then be reconciled with the Senate version.

Jack Lindley, Vermont Republican Party chair, said that he had been told by the law firm of James Bopp, a nationally renowned campaign finance attorney, that a legal challenge to the legislation is assured “within weeks” if the cap is enacted.

“I don’t see why taxpayers have to foot the bill for a fishing expedition that has no chance in court,” said Lindley. “They (representatives from Bopp’s firm) said Vermont has been the gift that keeps on giving. And we’ll continue to do so, with this legislation.”

House Republican minority leader Rep. Don Turner, R-Milton, warned his caucus about that likely quick lawsuit on Tuesday, citing Lindley’s correspondence. But the House Republican caucus won’t take an official position on the legislation, Turner said.

Bopp successfully beat the state in court over campaign finance legislation from 1997, which the U.S. Supreme Court struck down in 2006 as unconstitutional. Bopp argued in person against Attorney General Bill Sorrell in final oral arguments.

Bopp is also representing the Vermont Right to Life Committee  in ongoing litigation that Bopp lost in Vermont federal district court, but which he is now appealing in the federal 2nd Circuit Court of Appeals.

In a phone interview, Bopp wouldn’t say whether he would sue the state over such a cap, adding that he doesn’t comment on potential lawsuits.

But he added: “It’s perfectly clear that under the law that you cannot cap contributions to Super PACs. … Numerous courts have ruled that it is unconstitutional to limit contributions to them. This is just another foolish attempt by the Vermont Legislature to defy the Constitution.

“I have a number of clients who would be adversely affected (by such a cap), and they’d consider their options if that would come to pass,” he continued.

The House Government Operations Committee voted 9-2 to back such a cap, among other campaign finance provisions, late last week. Committee chair Rep. Donna Sweaney was persuaded in part by testimony from Harvard Law School professor Lawrence Lessig, who visited the committee in person recently.

Lessig has been described as a liberal and an activist by The Atlantic. In an 2011 interview with Rolling Stone magazine, he discussed his belief that Congress has become too dependent on fundraisers. He’s written a book on how Congress has been bought and corrupted by special interests.

Lessig told the committee recently he’s confident the state could defend such a cap in court, although Vermont Law School professor Cheryl Hanna doubted last week that the U.S. Supreme Court would uphold such a cap.

According to Assistant Attorney General Eve Jacobs-Carnahan, the state could defend the legislation by arguing that spending that isn’t coordinated with a candidate can still create political debts, and that capping donations enhances transparency by encouraging donors to spend on communications using their own name, rather than indirectly through a Super PAC.

The U.S. Supreme Court hasn’t yet ruled directly on donation caps to Super PACs, but in its 2010 Citizens United decision, it maintained that corporations and unions can raise and spend as much as they like, without disclosing their donors, so long as they act independently of political candidates.

A few federal appellate courts, including the D.C. circuit in its 2010 SpeechNow case, which relied on Citizens United reasoning, have struck down caps on donations to Super PACs. The 2nd Circuit, under which Vermont falls, has not ruled on the question.

But before any challenge hits the docket, the state Senate must approve the cap, which it previously made conditional on the outcome of ongoing litigation.

The Senate Appropriations Committee voted 7-0 to keep the cap conditional, citing fear of an expensive lawsuit. Sen. Jane Kitchel, D-Caledonia, said that a lawsuit could cost $2 million.

Sen. Dick Sears, D-Bennington, another Appropriations member, said an unconditional cap sounds “very risky.” He said he regrets his support of the 1997 campaign finance legislation, and would have changed his vote had he known about the potential costs.

“You also take the risk of other parts of your campaign finance laws being overturned,” said Sears, who believes Vermont’s earlier legislation could have indirectly prompted later Supreme Court decisions like Citizens United.

Bopp’s first lawsuit cost the state $1.6 million, of which $1.4 million went to Bopp’s and other attorneys’ fees, a mandatory payback when constitutional questions are at stake. Ongoing litigation in the Vermont Right to Life case has cost the state $164,000.

Jacobs-Carnahan doesn’t have a detailed estimate of how much a fresh lawsuit could cost the state, but said it could be “several million dollars” if the state lost.

Paul Burns, VPIRG’s executive director and a campaign finance watchdog, said that the coming negotiations between the House and the Senate on this bill should be worth watching.

“A number of very powerful senators are uneasy with an approach that would just ignore the ongoing litigation and put that cap into place,” Burns said. “So I think at a minimum, the House needs a Plan B if they want to see the overall legislation pass.”

Vermont’s two prominent and homegrown Super PACs have their own views on capping their funders.

Vermonters First, the conservative Super PAC that received $1 million from Burlington resident Lenore Broughton, said via founder Tayt Brooks that a cap only serves to suppress opposing views. He called the cap a push led by the “Democratic super majority.”

“Their goal here is remove any voices they see out there that may force the debate on critical issues. It’s disappointing to see them try to do this, but it’s not surprising,” Brooks said in a statement.

Priorities PAC, a liberal PAC founded by lobbyist Bob Stannard, takes a different view.

“Great idea,” Stannard said of the cap. “Cap ‘em. Get rid of them (Super PACs). … We’re not fans of Super PACs. Just because I have one doesn’t mean I like it.”

“Given the extreme pressure that unlimited money in campaigns puts on democracy, it’s the right aggressive step to take,” added Todd Bailey, a consultant and co-founder of Priorities PAC.

House Speaker Shap Smith backs the cap. Gov. Peter Shumlin didn’t respond to a request for comment, but has previously expressed wariness about a court battle over GMO labeling legislation, which the Joint Fiscal Office estimates could cost Vermont $5 mllion to $10 million.

Amendments to the cap and the legislation are expected on the floor in the final House debate on Wednesday.

Nat Rudarakanchana is a recent graduate of New York’s Columbia University Graduate School of Journalism, where he specialized in politics and investigative reporting. He graduated from Cambridge University...