STATE HOUSE, BOSTON, FEB. 23, 2015…..An Arizona-based conservative group plans to sue the Bay State’s campaign finance agency on behalf of two local businesses, arguing that Massachusetts has banned businesses from making political donations while allowing unions to contribute up to $15,000.

The lawsuit against the state Office of Campaign and Political Finance will be filed on Tuesday in Suffolk Superior Court by the Goldwater Institute and says “businesses and unions are functionally equivalent organizations.” The institute is named after the late Sen. Barry Goldwater, who unsuccessfully ran as the Republican nominee for president in 1964.

“There is no legitimate justification for allowing unions to contribute thousands of dollars to candidates, parties, and political committees, while completely banning any contributions from businesses,” the lawsuit says, according to a copy provided to the News Service.

The Goldwater Institute is filing the lawsuit on behalf of two businesses: 1A Auto Inc., which sells auto parts in Pepperell, and 126 Self Storage Inc., which rents out self-storage units in Ashland.

Rick Green is the president of 1A Auto Inc. and chairman of the Massachusetts Fiscal Alliance, a right-of-center non-profit also known as MassFiscal. The owner of 126 Self Storage is Michael Kane, who is also clerk and director for MassFiscal.

“We can’t compete with a union when it comes to supporting the type of candidates we want to support as a business,” Kane told the News Service.

A spokesman for OCPF declined to comment on the proposed suit, which alleges violations of free speech and equal protection under the U.S. and state constitution. When OCPF is sued, the state attorney general’s office often handles the case.

In a statement to the News Service last July while campaigning for attorney general, Democrat Maura Healey addressed what some were calling a “union loophole.” Healey said, “The corrupting influence of money in our politics comes when corporations and billionaires can spend millions to warp our political process, not from $15,000 in small, individual contributions collected from working people.”

Healey, who won in November, added that she would “lead the fight to reduce the influence of money in our political process” as attorney general.

Jason Tait, the OCPF spokesman, said current campaign finance law prohibits direct or indirect contributions by businesses to political candidates.

Individuals are limited to a $1,000 contribution per calendar year. But unions, trade associations and other organizations that do not have business money in their treasury are allowed to directly contribute up to $15,000.

During a campaign finance reform debate last year, Republican lawmakers sought to close what they see as a loophole benefiting unions, and bring the contribution limit down to $1,000.

But efforts in both the House and the Senate failed on largely party line votes. In the House, the tally was 29-120, and senators voted 10-28, with several Democrats joining the Republican caucus on the vote.

Sen. Marc Pacheco (D-Taunton) said during the debate that the rule “empowers working families who are members of unions so they can have just a little bit of a shot to try to come maybe half way to where those who can collect $1,000 contributions.”

But House Minority Leader Brad Jones (R-North Reading) on Monday called it an “obvious” loophole that disproportionately benefits Democrats.

Depending on how the lawsuit fares, Jones said the issue could “conceivably” surface on the campaign trail in the future.

Paul Craney, executive director of MassFiscal, said the group may end up using roll call votes on the issue in future mailings to voters, as they did in the 2014 election cycle in mailings and newspaper ads that pointed to votes on the gas tax, housing benefits and local aid. Democrats complained about the mailings, calling them misleading.

Everything is “on the table,” Craney said.

According to the Goldwater Institute, Massachusetts is one of seven states that ban businesses from contributions. The others are Iowa, Kentucky, Minnesota, Mississippi, Montana and West Virginia.

[Matt Murphy contributed reporting]

Copyright 2015 State House News Service