Political advertisements about the Employee Free Choice Act, sometimes called “card check,” are burning up the airwaves in Maine. Think it’s just another squabble between the left and the right? You’re wrong.

If card check passes, it would be a sweeping change in labor law for both employers and employees. No matter your political persuasion, business owners and the people who work for them need to understand exactly what this legislation would mean. Card check changes the way a union can be officially certified as the bargaining agent for a company’s employees.

In the current system, administered by the independent National Labor Relations Board, workers decide to unionize by voting in a private-ballot election.

Under the card check system, union organizers would just gather signed cards from 50 percent-plus one of the workers they want to represent. No private-ballot election required.

The union argument for card check boils down to the assertion that private voting doesn’t work because they’re not winning as many elections as they think they should. In a feat of mental gymnastics, labor leaders assert that voting in public is fairer than voting in private.

Twenty five years ago, trade unions in Maine represented 13 percent of construction workers. Now they represent just 4.2 percent. Labor leaders in Maine would have us believe their declining numbers are attributable to union-busting contractors bullying workers into voting against the union by wrongfully firing organizers and illegally threatening to close up shop.

Their solution? Get rid of that pesky voting.

Using card check, paid union organizers follow workers to company parking lots, visit them at their homes, even corner them in public at bars and restaurants, asking them to sign what amounts to a legally binding union contract (the “card”). It’s a situation ripe with the possibility of coercion from peers and intimidation from organizers. Workers targeted in card check campaigns have been known to sign just to end the harassment.

So, what about the 49 percent of employees who refused to sign the card? Since Maine allows compulsory unionism, those employees either join the union and pay their dues, or find a new job. Their employer is now obligated to negotiate with union bosses about their pay, benefits and work rules in a collective bargaining agreement — no more raises or promotions based on merit for a job well done.

If the employer and the union can’t agree on the terms of the collective bargaining agreement within 120 days, a federal arbitrator steps in, writes a binding agreement for them and locks it in for two years. This is an unprecedented government intrusion into private business practices.

Other elements of card check tip the balance in labor’s favor, too, including increasing back pay and civil fines if an employee is unfairly discharged or discriminated against.

The rules for decertifying the union don’t change. Workers can’t decertify the union while there’s a collective bargaining agreement in place or being negotiated, or if there are pending charges of unfair labor practices. And the decertification vote can only be done by secret ballot.

How’s that for irony?

Card check is organized labor’s highest legislative priority — their litmus test for politicians as they seek to reverse the downhill slide in union membership — and they’re putting their money where their mouth is, spending more than $300 million this election cycle to get their friends elected.

It’s already passed in the House of Representatives. Reps. Tom Allen and Mike Michaud supported the legislation — sponsored it, in fact. Sens. Susan Collins and Olympia Snowe say they’ll stand up for worker rights and vote to protect private ballots. Presidential candidate John McCain has promised a veto, but his opponent, Barack Obama — also a co-sponsor — has said he’ll gladly sign it.

In a recent Wall Street Journal column, former Sen. George McGovern (D-S.D.), champion of organized labor, called card check “a disturbing and undemocratic overreach not in the interest of either management or labor,” adding that it “runs counter to ideals that were once at the core of the labor movement. Instead of providing a voice for the unheard, it risks silencing those who would speak.”

There’s no freedom for employees in the Employee Free Choice Act. The only way to protect an individual worker’s freedom to choose without coercion is through the continued use of federally supervised, private-ballot elections so that every worker can make an informed, private decision in a voting booth when confronted with the choice to unionize.

It’s a fundamental American right — one the left shouldn’t be so quick to bargain away.

Kathleen McGibney Newman is president of the Associated Builders and Contractors of Maine.