Just a few days after President Obama said he would more than double the wage level for workers before employers can legally exempt them from being paid overtime, business groups are already plotting to fight the rule in the few months the government needs to finalize it.

Their efforts will be focused on the proposal's upcoming "public comment period," the part of the regulatory process where the government solicits outside opinions before it decides on the final version of a rule.

The process is technically little more than a courtesy, since federal agencies can ignore the comments if they want. But it's nevertheless a key battlefield in all federal regulatory efforts, and the comment period tends to shape the legal and legislative fights that will follow once a final rule is out.

The comments essentially signal to the agency what interested parties, mainly business coalitions, nonprofit groups and lawmakers, object to in a proposed rule. An agency that doesn't take their concerns into account can be assured of either court challenges, congressional efforts to roll back the rule, or both. In the case of court battles, challengers will have stronger legal standing if they can show the agency ignored their comments.

"It is important because the agency is supposed to consider that input when it crafts a rule," said Dan Bosch, senior manager for regulatory policy for the National Federation of Independent Business. "If the comments are all one-sided ... then the agency wouldn't have a leg to stand on to justify the rule being the same as what they proposed."

Bosch said one thing his members would be emphasizing is the blanket nature of the rule, which will hurt them because managers count on being able to negotiate work schedules with their employees.

The comment period is required as part of the Administrative Procedures Act, the 1946 law that governs federal rulemakings. The law is the reason why federal regulations don't happen with the stroke of a pen. Even activist administrations must wait months to put a new rule in place, even in cases where the rulemakings can bypass Congress.

"The administration seems to have their mind made up about the direction they want to go in (for the overtime rule) but under the Administrative Procedures Act, they have to contemplate our comments. They have to take them into account and respond to them," said David French, senior vice president for government relations at the National Retail Federation.

The volume of comments matters too, so groups like NFIB and NRF urge their individual members to submit comments as well. Other groups like labor organizations and non-profit activist groups weigh in as well using similar tactics. Groups whose members are directly affected, and therefore have a stake in the outcome, usually have the edge.

The Obama administration is aware of industry tactics and acted to blunt them. French noted that the administration set a 60 day period for accepting comments on the overtime rule, basically July and August.

That's an unusually short for a high-profile rulemaking, which in other cases are often as along as 180 days. One of the first things his group will is request an extension of the filing period, French said.

Administration officials are not above a bit of ballot-box stuffing either. In May, a New York Times report found that the Environmental Protection Agency had been soliciting environmental groups through the Internet and social media to submit comments backing its latest rulemaking under the Clean Water Act. The effort appeared to violate rules prohibiting federal agencies from lobbying the government.

"I have not seen before from a federal agency this stark of an effort to generate endorsements of a proposal during the open comment period," Jeffrey W. Lubbers, a professor of administrative law at American University, told the Times about the EPA's effort.

If the agency doesn't meet the industry half-way, lobbying Congress to limit the agency's rule was one common response in previous years. Business groups say that's has been a less effective option in recent years due to congressional gridlock, though attaching language rolling back a new rule to a must-pass budget bill might still tried.

Lawsuits are a last resort, notes Bosch, but one they won't shy away from using. "I'm sure if we see a final rule like what the administration has proposed, someone, if not many people, will challenge it in court," he said.

Business groups have had their biggest successes against the administration there. On Monday, the Supreme Court threw out the Environmental Protection Agency's proposed revisions to the Clean Air Act, saying the agency had not taken into account the impact the new rules would have on industry.

Chamber of Commerce President Tom Donohue said at a March policy forum that suing the government had become his organization's main tool. "We spend half of our time trying to reduce the number of suits by class-action lawyers and the other half of our time suing the hell out of the government."

Donohue said the Chamber sues the federal government almost 200 times a year. "We have got the best people and the best track record and the best results in this city," he said.