We knew the unions wouldn’t let the lame duck session pass by without extracting some big payback for all the time, effort, and money they put into creating the Democratic congressional majority.

Senator Tom Harkin had promised a push for card check, but that was a bridge too far. We are worried about pension bailouts, but they don’t seem to have the votes for that (but stay on red-alert). But of course the unions aren’t going to sit out their last chance for a long time to work with a Democratic Congress.

The unions are now making their first big push for lame duck payback, and it’s S. 3194, the so-called "Public Employee-Employer Cooperation Act." Per usual, it has a wonderful name that is more or less the opposite of what the bill actually is—an unnecessary, expensive, and harmful bill that would force state and local governments to recognize union bosses as the exclusive bargaining agents for public-safety workers. A vote on may come later this week.

This bill violates the basic tenets of our federalist system of government. Local governments should not be forced by Washington, D.C. to impose forced unionization on their police, paramedics, and firefighters.

This bill is an unfunded mandate on state and local government that will force a higher tax burden at the state and local levels. It would strengthen public employee unions by forcing more workers into them when they are already strangling state and local governments fiscally.

Unfortunately, this legislation has broader Republican support than the other pieces of the union agenda, possibly because some police and firefighter unions have historically supported Republicans.

There is also a geographic factor, because strong union states included the Northeast already have mandatory collective bargaining for these workers.

So senators from these states see political upside without any meaningful downside for their states, and are poised to impose the crippling costs of forced unionism on other states, including the right-to-work South where public employee unions are generally nonexistent.

But there is significant downside even for states that already have mandatory collective bargaining, because a federal mandate would tie the hands of state governments and prevent crucial reforms to weaken the public employee unions. That’s essential to move forward on pension reform and other key state-level budget fights.

The lead sponsor of an earlier version of the bill is a Republican, Senator Judd Gregg of New Hampshire. One of the lamest of lame ducks, Gregg is retiring. He is also a member of Obama’s fiscal commission, making it ironic that he would impose the enormous costs associated with forced unionism on the states.

His successor, Senator-elect Kelly Ayotte, should call on Gregg to do the right thing and pull his support for the bill.

Regardless of his position on it, it is inappropriate to disregard a national election—fueled in part by a backlash against the influence of public employee unions—by enacting a major policy change like this one in a lame duck session.

Other Republican co-sponsors include Senators Scott Brown of Massachusetts, Susan Collins and Olympia Snowe of Maine, Mike Johanns of Nebraska, and Lisa Murkowski of Alaska.

Collins, Snowe, and Johanns have taken strong public stands against doing this type of legislating in a lame duck session, and voters should watch carefully whether they keep their promises.

Collins said she was “not going to play that game.” That passing left-wing policies in the lame duck would be "just wrong" and "blatantly against the will of the people.”

Snowe said: “As a strong advocate for limited government and responsible governance, I share the concerns over the potential lack of accountability inherent in a lame duck session.”

This vote will put both Maine senators to the test.

Sen. Mike Johanns of Nebraska, has said Congress should stick to only the must-pass issues of funding government and extending the expiring tax cuts. And Johanns is a conservative who should know better than to support forced unionism, anyway.

One notable Democratic co-sponsor is lame duck Sen. Russ Feingold of Wisconsin. Feingold had this to say about lame duck sessions on the campaign trail: “By allowing votes just after an election but before the newly elected Congress takes office, lame-duck sessions provide an opportunity to override the public's will as expressed at the ballot box.”

These senators should keep their promises, and any senator who votes to jam this forced-unionism scheme through the lame duck session should be held accountable by voters.

Mr. Kerpen is vice president for policy at Americans for Prosperity, which is fighting the lame duck session on the web at www.NovemberSpeaks.com.