The specter of voter intimidation in all its guises, from sensational billboards to aggressive poll watchers to threats from employers, hangs over the 2012 elections.

The notion that voters deserve protection from coercive tactics is as old as the Republic. As early as the 1700s, laws in several colonies and states barred any “attempt to overawe, affright, or force, any person qualified to vote, against his inclination or conscience,” Eugene Volokh, a law professor at the University of California at Los Angeles, noted in a recent paper.

Workplace intimidation, in particular, has raised alarms in the wake of the Supreme Court’s 2010 ruling in Citizens United v. Federal Election Commission. That decision not only permitted unrestricted spending by corporations and unions on independent campaign activities, but also freed them to more actively educate workers about elections through voter guides, get-out-the-vote activities and other tools.

Some employers appear to have jumped right in. Recent news reports have detailed emails to employees from CEOs at companies including Koch Industries’ Georgia-Pacific, Westgate Resorts, Lacks Enterprises and ASG Software Solutions warning that a vote against GOP presidential nominee Mitt Romney would, essentially, lead to layoffs.

Romney appeared to encourage such talk when he addressed business owners on a conference call with the National Federation of Independent Business. “I hope you make it very clear to your employees what you believe is in the best interest of your enterprise and therefore their job and their future in the upcoming elections,” he said. The magazine In These Times first reported Romney’s comments this month.

“This amounts to calling for employers to bully working people in their workplace,” AFL-CIO President Richard Trumka said in a statement this month.

To unions, political messages from employers bring to mind the type of mandatory meetings aimed at squelching union organizing efforts that are barred by labor laws. AFL-CIO organizers are watching reports of employer politicking closely and are hoping their allies in Congress take notice.

“Everybody recognizes, I think, that this is an inherently intimidating situation,” said AFL-CIO Associate General Counsel Laurence Gold, a partner at Trister, Ross, Schadler & Gold.

But unions have also faced charges of intimidation. In July, a local affiliate of the American Federation of State, County and Municipal Employees known as United Public Workers agreed to pay a $5,500 fine as part of an agreement with the Federal Election Commission after an employee complaint. The worker alleged that she and a colleague were fired after refusing to donate to and get out the vote for now-Rep. Colleen Hanabusa (D) in Hawaii’s 1st district special election in 2010.

Despite the fine, the FEC stalemated over whether the union broke the law. The three Republican FEC commissioners concluded that, in view of the Citizens United ruling, “requiring employees to work on independent expenditures for either the union or non-connected political committee is not a violation of the Act or Commission regulations.” But the commission’s three Democrats concluded that “nothing in Citizens United” expanded the rights of unions and corporations “at the expense of their employees’ longstanding rights to be free from coercion” and to hold “their own political views.”

The split underscored the unsettled state of the law in the wake of Citizens United. In theory, the ruling dramatically frees employers of all stripes to try to influence their workers’ political action. If Citizens United permits corporations to invest their resources in politics, former FEC press officer Bob Biersack said, then employees might be considered resources that firms can mobilize.

“In theory, now every corporate account is available for really aggressive campaigning,” said Biersack, a senior fellow at the Center for Responsive Politics.

But compliance lawyers warn that FEC regulations have yet to be updated to reflect the Citizens United ruling.

“Technically, the law may provide new freedoms,” said James Kahl, who leads the political law practice at Womble Carlyle Sandridge & Rice. “But regulations have not been rewritten, and people don’t want to violate existing regulations.”

The absence of new FEC rules leaves employers in “kind of a no-man’s-land right now,” added Kahl, the FEC’s former deputy general counsel.

In fact, employers enjoy considerable leeway to predict outcomes to their employees, including an election’s negative effect on a company, Volokh said. The key distinction is between messages that constitute “overtly, a threat of retaliation,” versus a “prediction of dire economic consequences,” he said.

At the same time, federal criminal statutes make it unlawful to “intimidate, threaten, or coerce, any other person for the purpose of interfering with the right of such other person to vote or to vote as he may choose” for candidates up and down the ballot.

And employers who step over the line lose credibility with workers, said Greg Casey, CEO of the Business Industry Political Action Committee. BIPAC is using mobile applications and social networking to help up to 7,000 employers educate their workers on public policy issues this year through its Prosperity Project. Virtually all BIPAC-endorsed candidates are Republicans.

It’s all perfectly legal and, according to Casey, doesn’t amount to a campaign expenditure. He said the employers are not telling people how to vote.

“Intimidation and coercion is not acceptable in the workplace, whether it’s practiced by management or by labor,” Casey said.