As the presidential race gets tighter, nastier, and closer to the finish line, some expect outside political groups to start advertising heavily, as they did at this stage in the 2004 election.

There have been hints that neither Barack Obama nor John McCain would be broken-hearted if their allies among politically active 527 and nonprofit groups pulled out the big guns, contrary to their previous declarations. Recent reports suggest that Obama's not likely to raise objections if friendly labor and progressive activist groups start making some noise, and McCain recently told the Boston Herald: "I can't be a referee of every spot run on television."

But advocacy and 527 groups eager to jump into the controversial game that the Swift Boat Veterans for Truth perfected four years ago may find that the rules are a lot stricter this time around.

"There's no question that 527 groups are in a much more risky environment than they were in 2004," said Fred Wertheimer, president of Democracy 21.

A federal court ruling on Sept. 11 beat back a challenge to Federal Election Commission restrictions on independent political groups. A 527 group dubbed The Real Truth About Obama Inc. had sought an injunction that would have allowed it to use unregulated money to run ads critical of Obama's abortion stance.

In his order denying the injunction, federal judge James R. Spencer of the U.S. District Court for the Eastern District of Virginia wrote that "a grant of these injunctions would negatively impact the public." Conservative lawyer James Bopp Jr. will now seek an expedited appeal.

"There was the potential for this case to open the floodgates of unlimited spending by outside groups that are determined to influence the presidential election," said Paul Ryan, an attorney for the Campaign Legal Center, which had joined with campaign finance watchdog Democracy 21 in an amicus brief challenging the anti-Obama group.

As it is, the ruling adds to a series of sanctions and warnings from federal officials on outside groups. The FEC has imposed some $1.4 million in fines on high-profile 527 groups active in 2004, including the Swift Boat organization.

Deputy Assistant Attorney General John C. Keeney, moreover, has signaled that Justice Department attorneys "intend to vigorously pursue instances where individuals or organizations knowingly and intentionally violate the clear commands of" the Federal Election Campaign Act. All that may help explain why there's been substantially less activity by 527 groups in this election than there was four years ago.

"There's no question that 527 groups are in a much more risky environment than they were in 2004," said Fred Wertheimer, president of Democracy 21. "And the refusal of [Judge Spencer] to issue an injunction here simply increases the potential for liability for 527 activity."

Not that 527s, advocacy groups and other outside political players aren't weighing in this year.

One new anti-Obama group attracting attention is the American Issues Project Inc., which has announced plans to spend $3 million in unregulated money on anti-Obama TV ads.

The group claims that it's a qualified nonprofit corporation that's exempt from FEC restrictions under a 1985 Supreme Court ruling, FEC v. Massachusetts Citizens for Life. That ruling found that nonprofit corporations that make independent expenditures and take no labor or union money are not subject to campaign finance limits. The Obama campaign has reportedly asked the Justice Department to investigate.

Also generating some buzz is a Democrat-friendly 527 group dubbed the American Leadership Project, which has been running ads that it says highlights "issues of importance to the American middle class," such as the economy, jobs, health care costs and the mortgage crisis. That group ran ads favorable to Hillary Rodham Clinton during the Democratic primary campaign -- prompting complaints to the FEC by both Obama supporters and the Obama campaign.

Now the American Leadership Project is running ads critical of McCain -- and the Obama camp has been noticeably silent. Some bloggers and conservatives have asked why, prompting Democratic lawyer Bob Bauer, who's representing Obama, to explain that it's McCain's job, not his, to respond to attacks on the Republican.

Another group that will be closely watched is Leadership for America's Future, a new conservative 527 group. The group's Web site touts its intent to foster a discussion "on the kind of leadership" America needs in the 21st century.

The Center for Competitive Politics, a First Amendment advocacy group, recently defended the right of Leadership for America's Future to speak out on public issues. "There's a constitutional right for citizens to associate and to speak out on issues, even when that speech occurs near election time," said Reid Alan Cox, legal director for the Center for Competitive Politics.

Whatever the risks for 527s and other outside players, Swift Boat season has arrived. "We are now entering the period when these groups may become active and visible," noted Ryan, of the Campaign Legal Center. "They demonstrated in 2004 that they have the capacity to raise huge amounts of money in short periods of time and to use that money to great effect in presidential elections."

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