Three weeks ago, James Dobson -- who hosts a daily radio show syndicated on 3,000 stations nationwide -- devoted his entire half-hour talk show to a policy that has been defunct for decades.

Dr. Dobson, who is also chairman of the conservative organization Focus on the Family, fears that the Fairness Doctrine, an FCC measure that required radio stations to present both sides of issues of public concern, is headed for a comeback.

He's not alone.

The doctrine was withdrawn in 1987 under President Reagan's sweeping deregulation program, and the FCC has not sought to enforce it since then. With the 2008 election fast approaching, however, conservative pundits and politicians worry a Democratic victory could mean the demise of talk radio's conservative stars like Rush Limbaugh and Sean Hannity.

"All it takes is one appointment to the FCC of someone who would want to bring this back and there you go," said Matt Lloyd, spokesman for Rep. Mike Pence, R-Ind., a former talk radio host who is leading the legislative crusade against the return of the doctrine.

Ashley Horne, a federal policy analyst for Focus on the Family, said it was "rumblings in Congress" that initially raised the organization's concern and prompted Dr. Dobson's segment on the issue. Focus on the Family believes a reinstated Fairness Doctrine would try to sanitize shows like Dr. Dobson's.

"If he were to talk about abortion ... then stations carrying his broadcast could be required to bring in opposing viewpoints," said Ms. Horne. Christian stations "would choose to not air those topics at all rather than bring in a representative from Planned Parenthood," she said.

In the past month, discontent over the issue has grown louder, reaching a small roar after Speaker of the House Nancy Pelosi, D-Calif., in answer to a question at a Christian Science Monitor breakfast with the press, said she would support the revival of the Fairness Doctrine.

Despite Ms. Pelosi's remark, few Democrats expect the Fairness Doctrine to return if the party prevails in November.

Instead, experts say, reforms are likely to concentrate on reducing media consolidation and encouraging local programming. Media ownership caps would target companies like Clear Channel Communications -- which operates more than 1,200 radio stations in the United States -- by limiting the number of stations a single entity could own.

"That's where the fight is going to come," said Clay Calvert, co-director of the Pennsylvania Center for the First Amendment and author of "Mass Media Law," the top-selling undergraduate media law textbook in the nation.

The fight is not likely to be over reinstating the Fairness Doctrine, a move that presumptive Democratic presidential nominee Sen. Barack Obama opposes.

"Sen. Obama does not support reimposing the Fairness Doctrine on broadcasters," Obama spokesman Michael Ortiz, said in an e-mail. "He considers this debate to be a distraction from the conversation we should be having about opening up the airwaves and modern communications to as many diverse viewpoints as possible."

His Republican opponent, Sen. John McCain, R-Ariz., would not seek to re-enforce the doctrine, either.

"Sen. McCain believes the federal government should not be in the position of policing the airwaves," said McCain spokesman Paul Lindsay.

"It's not in the cards," said Rory O'Connor, author of "Shock Jocks: Hate Speech and Talk Radio."

Because the Fairness Doctrine was based on the limited number of available airwave frequencies when it was formalized in 1949, Mr. Calvert said, it would be outdated in an era with so many media options, from cable to the Internet.

"Marketplaces determine the public interest and not the government, and that has been the stance since 1987," he said.

"I don't think anybody is interested in regulating free speech," echoed John Halpin, a senior fellow at the Center for American Progress, a liberal think tank.

Mr. Halpin co-authored a report last year titled "The Structural Imbalance of Political Talk Radio." The study, which found 91 percent of weekday talk radio to be politically conservative, is referred to often by those who fear Democrats are gunning to "Hush Rush."

The report offered three policy suggestions: restore media ownership caps, provide for "greater local accountability" in radio licensing and require owners who do not abide by "enforceable public interest obligations" to pay a fee to support public broadcasting.

But Mr. Halpin said he and his colleagues are not calling for the reinstitution of the Fairness Doctrine. "We don't think it would work."

Even Al Franken, former host of an Air America liberal radio talk show and now the Democratic candidate for the U.S. Senate in Minnesota, said he would not support the return of the doctrine.

"The public owns the airwaves, but I think this is an odd imposition of governmental power," said Mr. Franken. "I'm uncomfortable with it, even though I see how unbalanced radio is and I can't stand it.''

Still, Mr. Pence and some of his Republican colleagues think the Fairness Doctrine is enough of a threat to require pre-emptive action.

One year ago, Mr. Pence introduced the Broadcaster Freedom Act, which Mr. McCain co-sponsored, but Ms. Pelosi has declined to schedule a vote on the bill. Mr. Pence is currently gathering signatures for a discharge petition to force the bill onto the floor of the House.

When asked about claims that Democrats would not seek to reinstate the doctrine if they won the presidency in 2008, Mr. Lloyd, the Pence spokesman, said he did not buy them.

"You could count me, along with a number of other Republicans, skeptical," he said.

In particular, talk of increased "broadcast localism" has raised hackles. Some say such policies would have the same end as the Fairness Doctrine.

"Localism is a stealth Fairness Doctrine," Mr. Lloyd said.

FCC proposals that would require radio licensees to meet periodically with advisory boards composed of community members are pending review.

"Anything that produces complaints is going to be taken off the air, including Rush Limbaugh," said Jim Boulet Jr., executive director of conservative lobbying group English First and a vocal opponent of localism. "When Obama says we don't need the Fairness Doctrine, it tells me he knows how effective localism is going to be."

Mr. Halpin disagreed with the charge that the Center for American Progress's suggestions would be "legislation by stealth."

"It's not focused on talk radio," he said. "It's the same criticism that leads to the bland programming on the music side, where you get stations that play the same pop music."

According to FCC spokeswoman Edie Herman, "There's no connection between these localism proceedings and the Fairness Doctrine."

"There is a real existential fear on the right about this," said Mr. O'Connor, the "Shock Jocks" author, who referred to the spectre of the Fairness Doctrine as a "bogeyman."

"I think this is a way for conservatives to gin up victim mentality in the middle of an election year," said Mr. Halpin, who pointed out that Rush Limbaugh received a $400 million contract renewal just recently.

"I'm sure we contributed to Rush's $400 million," Mr. Halpin joked. He said the Center for American Progress's report is frequently misinterpreted as advocating the return of equal time for opposing views.

"We're not asking for mandated balance," he said. "Talk radio is a medium that conservatives are drawn to. I'm sure there will always be a greater audience for conservative talk."

In the end, said Mr. Calvert, of the First Amendment Center, the disagreement boils down to a clash of political principle: Conservatives believe the government should not meddle, and liberals believe in the power of regulation.

The reign of Mr. Limbaugh is not likely to come to an end anytime soon, most experts say.

Either way, the 2008 election will be a turning point, Mr. Calvert said, pointing out that the FCC has just five commissioners, and the next president will appoint a new head.

"Whoever becomes president is going to have a huge say."