Way back in 2008, reality star Heidi Montag told reporters that she supported John McCain for president. She also said she didn’t think anyone cared whom she supported for president.

How wrong she turned out to be. The current era of social media has proved that even minor celebrities like Ms. Montag, with her 1 million Instagram followers, are not only in demand but can also earn serious dollars for their two cents.

Paid influencer advertising is so common that the Federal Trade Commission years ago created rules about disclosing financial relationships between brands and the influencers who lend their stamps of approval to them. The requirement, though, has never applied to political content.

The Federal Elections Commission wants to change that. It is looking at a rule that would define “Internet public communications” to include posts that support or reject federal candidates and are “promoted for a fee” on third-party websites like social media platforms. 

“You’d think that people should know who actually paid for that message when they hear it in order to better evaluate it,” a former FEC commissioner and senior counsel at Perkins Coie, Karl Sandstrom, told the Sun. 

The problem, opponents say, is the vagaries of the rule. 

“‘Promoted for a fee’ may sound fine on the surface but lurking below the radar, it is ambiguous terminology that needs to be defined because it could cause a situation where the internet goes from being pretty much unregulated to where every post that’s political, advocating for or against the election of a federal candidate, gets regulated by the Federal Election Commission,” the president of Citizens United, David Bossie, told the Sun. 

Mr. Bossie said private communications among paid internal staff, consultants, or others involved in the production of content appearing on third-party websites could be swept up into “public” communications. That ambiguity is an anvil that could curb free speech, he said.

“The more vague the terminology, the more it lends itself to overreach and unintended consequences,” he said.

The commission began updating its rules on public internet communications a year ago, but the supplemental proposal arose in December after fresh examples of content “promoted for a fee” arose during the midterm election.

The most prominent was a video made by a “Jersey Shore” reality star, Nicole “Snooki” Polizzi, who is a paid supporter of Senator Fetterman of Pennsylvania. 

Mr. Fetterman shared a message recorded in July in which Ms. Polizzi, standing in what appears to be her closet, calls herself a “hot mess” before trolling Mr. Fetterman’s opponent, Mehmet Oz, about his move to Pennsylvania from New Jersey to qualify to run for the Senate seat. 

She jokes not to worry, Dr. Oz will be welcomed home soon, meaning he would move back to New Jersey. The publicity value was high for Mr. Fetterman: The post was shared by his followers and Ms. Polizzi’s fans, and was covered by several celebrity and political news media outlets. Ms. Polizzi reportedly earns $3,500 for her recorded cameo.

While candidates must place disclosures on their advertisements and report payments for celebrity appearances, Ms. Polizzi’s post created a new distinction: Should she have been required to add a disclosure on a creation of her own making? 

Supporters say such a requirement would be a push toward basic transparency in elections.

“Requiring disclaimers on promoted content is the simplest and least burdensome way to protect voters, ensuring they are clearly informed when they are viewing paid political advertising through promoted content,” the Campaign Legal Center wrote in its comment to the election commission.  

Others say such a requirement would have a chilling effect on debate in what is now effectively the public square. 

“Average participants in online political discussion will face extraordinary challenges in discerning and complying with their regulatory obligations, and they may decide simply to abstain from political speech altogether,” Berin Szoka and Ari Cohn of TechFreedom, a nonprofit, nonpartisan technology policy think tank, wrote in comments to the elections commission. 

Platforms have tried to police political advertising on their own. Facebook requires verification of posters and disclosures before allowing paid ads on social and political issues. In September, TikTok announced that it would prohibit politicians and political parties from advertising at all, and that it will crack down on creators who are paid to make branded content for a political campaign. 

Even after TikTok’s announcement, production houses and influencers with connections to political financial backers were creating short videos that looked organic but were not, the clinic lead at Princeton’s Center for Information Technology Policy, Mihir Kshirsagar, told the Sun.

“An important way young people are getting information is through these kinds of social media websites, through social media accounts run by different entities, and so that’s what you need, disclosures, to know who is behind the video,” said Mr. Kshirsagar, who supports the proposed rule.