Attorney Robert Kennedy Jr.’s attempt to stop this year’s first presidential debate from happening would depend on enforcement action from one of the least active federal agencies.

CNN is to host the debate on June 27 and set a deadline of midnight on June 20 to qualify. Mr. Kennedy has not met the network’s requirements to participate and appears unlikely to do so by the end of the day Wednesday.

The first problem for Mr. Kennedy is that he has not attained ballot access in enough states to win 270 electoral votes, one of two requirements set by CNN. So far, Mr. Kennedy has only officially qualified for ballot access in six states accounting for 89 electoral votes, though the Kennedy campaign claims to have completed the required petitioning in states accounting for 310 electoral votes.

For instance, the campaign claimed to have gained ballot access in Mississippi, saying that his “We the People” party was “officially on the ballot.” Yet the secretary of state there said that it had not yet filed the necessary documents to gain ballot access.

CNN is also requiring candidates to receive 15 percent support in at least four qualifying polls in order to appear on the debate stage. So far, Mr. Kennedy has received at least 15 percent support in three such surveys.

Mr. Kennedy’s campaign has also filed a complaint with the Federal Election Commission alleging that CNN’s requirements violate federal campaign finance laws. The complaint hinges on the fact that neither President Biden nor President Trump are yet technically the nominees of their respective parties, and thus do not qualify to appear on any ballots, let alone enough to reach 270 electoral votes.

Both the Biden and the Trump campaigns have pointed out that they are their party’s presumptive nominees. However, the FEC does not generally make this distinction in this context, with the Commission on Presidential Debates noting,  “Until the conventions take place, we don’t know who the official nominees will be.” 

While the FEC declined to dismiss the complaint, it’s not clear whether it will be resolved ahead of the debate. The Kennedy campaign has, though, asked the FEC to prevent CNN and the other campaigns from holding the debate until they “come into compliance” with the relevant rules.

While Mr. Kennedy has called on the FEC to put the debate on hold unless he is allowed to participate, any enforcement action from the commission would have to overcome the notorious deadlock at the FEC’s board. The commission is made up of six commissioners, three Republicans and three Democrats, meaning the board is deadlocked the vast majority of the time it has to vote on an action.

In a 2017 report, the FEC commissioner, Ann Ravel, cited deadlock as a key factor in the “unlikelihood of draining the swamp,” noting that for “nearly every case of major significance over the past several years, the Commission has deadlocked.”

Yet a Republican commissioner, Sean Cooksey, has called the deadlock an “important structural feature” of the commission that prevents it from engaging in “partisan” investigations.

Mr. Kennedy’s efforts to participate in the debate aside, Mr. Biden and Trump are set to participate in an unusually early presidential debate with a set of strict rules agreed to by both campaigns.

In a memo outlining the Biden campaign’s debate strategy, Mr. Biden’s campaign chairwoman, Jen O’Malley Dillon, described a three-pronged attack on Trump, highlighting how he “continues to embrace political violence,” “wants to go even further” on abortion restrictions, and how his economic plan “would make him and his friends richer and jack up costs for the middle class.”

Since then, Mr. Biden’s campaign’s communications director, Micahel Tyler, has highlighted Trump’s criminality and his campaign’s focus on retribution, raising the question of whether Mr. Biden will criticize Trump for his recent felony conviction. “Trump approaches the first debate as a convicted felon who continues to prove that he will do anything and harm anyone if it means more power and vengeance for Donald Trump,” Mr. Tyler said.

At the same time, Trump’s campaign spokeswoman, Karoline Leavitt, has said that the “contrast between President Trump’s strength and success versus Crooked Joe Biden’s weakness, failures, and dishonesty will be made clear on the debate stage next week.”

An advisor to Trump, Jason Miller, has also suggested that Mr. Biden will be “shot up with chemicals,” something conservative pundits like Fox News’s Sean Hannity have suggested ahead of the debate as well.

“President Trump takes on numerous tough interviews every single week and delivers lengthy rally speeches while standing, demonstrating elite stamina,” Mr. Miller said in a statement.

One open question is whether Trump will invoke the recent conviction of Mr. Biden’s son, Hunter Biden, for lying on a form about his drug use while buying a gun. The catch is that, unlike in 2020, when Mr. Biden famously told Trump to “shut up, man,” the candidates will have to convey their political messages and air their personal grievances under a new set of rules.

According to CNN rules, each candidate’s microphone will be muted in order to prevent interruption while the other is speaking — a major shift from earlier presidential debates and even from recent GOP primary debates.

There will also be no studio audience and candidates will not be allowed to have pre-written notes, though they will be given note-taking tools. Candidates will also not be allowed to get help from aides during breaks.

The debate will be moderated by Jake Tapper and Dana Bash of CNN and will run for about 90 minutes, including two commercial breaks.

Neither Mr. Kennedy’s campaign nor the FEC immediately responded to requests for comment.