Last month, Elon Musk posted on X that President Biden “obviously barely knows what’s going on.”

“He is just a tragic front for a far left political machine,” Mr. Musk wrote. It was the 29th time this year that he had posted about the president on X, formerly known as Twitter, which Mr. Musk bought in 2022.

Mr. Musk has steadily ramped up his criticism of Mr. Biden as the campaign season heats up before the November presidential election. Mr. Musk has posted about Mr. Biden on X at least seven times a month since January, attacking the president for everything from his age to his policies on immigration and health. Before that, he posted about Mr. Biden twice in December and not at all in November, according to a New York Times analysis. In all, Mr. Musk had posted nearly 40 times about Mr. Biden this year, compared with about 30 times for all of last year.

In contrast, Mr. Musk had posted more than 20 times on X this year about former President Donald J. Trump, the presumptive Republican nominee. In those posts, Mr. Musk defended Mr. Trump, arguing that he is a victim of media and prosecutorial bias in the criminal cases that the former president faces.

Mr. Musk’s posts about this year’s presidential race stand out because he is signaling a willingness to tip the political scales as the owner of an influential social media platform, something that no other leader of a social media firm has done. And Mr. Musk exerts outsize influence over the political discourse on X, where he regularly posts to his 184 million followers.

Mark Zuckerberg, Meta’s founder, has shied away from endorsing candidates and rarely posts political content on Facebook or Instagram. Satya Nadella, Microsoft’s chief, and Sundar Pichai, Google’s chief, have also not posted political commentary on their companies’ social media platforms, LinkedIn and YouTube.

Bhaskar Chakravorti, the dean of global business at the Fletcher School at Tufts University, said Mr. Musk’s outspokenness on his political views could have consequences.

“He has ownership and the largest follower base, and he is a much-larger-than-life character with almost godlike status” on one of the largest platforms for political discussion, Mr. Chakravorti said. “If he was to really come out and support a candidate and put his weight against it, it could have an impact.”

The White House, the Biden campaign, Mr. Musk and X did not respond to requests for comment.

By bringing an ideological bent to X, Mr. Musk mirrors what media moguls like Rupert Murdoch, whose empire includes Fox News and The New York Post, have done by helping shape their outlets’ coverage and broader political discourse, said Sarah Kreps, a professor and director of the Tech Policy Institute at Cornell University.

Mr. Murdoch “has a particular ideological valence and most people know what that is, and that permeates through his different media outlets,” she said. “People can opt into those or opt out,” similar to X. Some users — put off by Mr. Musk’s ideological bent — have migrated to competing social media platforms, she said.

Still, Mr. Musk is unlikely to tip November’s vote, social media experts said. Many of his followers already agree with his political stance, they said, and the platform has shifted right since his acquisition.

Mr. Musk has become more publicly supportive of right-wing candidates and views in recent years. As recently as 2022, he described himself as a centrist and a reluctant Democrat. He said he voted for Mr. Biden hesitantly in 2020. Political giving records show that Mr. Musk has not made national campaign contributions since 2020, when he gave to Republican and Democratic Senate candidates.

But in June 2022, Mr. Musk said he had voted for a Republican candidate for the first time in a special election for Texas’ 34th Congressional District. In the national midterm elections that November, he urged voters to vote Republican in congressional races since a Democrat was in the White House.

That evolution continued last May when Mr. Musk hosted a buggy audio stream on X to announce and endorse Florida’s governor, Ron DeSantis, for the Republican presidential nomination. Mr. Musk has not made another endorsement.

Mr. Musk has also repeatedly used X to vocally support right-wing politicians around the world, including Javier Milei, the president of Argentina; Jair Bolsonaro of Brazil; and Narendra Modi of India. He has then tried to use that good will to lobby for advantages in those countries for his other businesses, including SpaceX, a rocket company, and Tesla, which makes electric cars.

Mr. Musk has courted Mr. Trump, who was booted from X when it was still known as Twitter, after the Jan. 6, 2021, riot at the Capitol. After buying Twitter in 2022, Mr. Musk moved quickly to restore Mr. Trump’s account, although the former president has posted only once on the platform since then.

Even though Mr. Musk has not endorsed Mr. Trump, he has had several conversations with the former president. In March, Mr. Musk and Republican donors met with Mr. Trump in Palm Beach, Fla., as the former president sought election donations.

Afterward, Mr. Musk posted on X that he was “not donating money to either candidate for US President.”

Mr. Musk has been sympathetic to Mr. Trump in his posts. “The more unfair the attacks on Trump seem to the public, the higher he will rise in the polls,” Mr. Musk wrote last week.

Mr. Musk has long been critical of Mr. Biden. In 2021, the billionaire slammed Mr. Biden for his decisions on electric vehicle promotion and subsidies, most of which favored unionized U.S. auto manufacturers. Tesla, where Mr. Musk is chief executive, has resisted efforts to unionize its manufacturing.

“My preference for the 2024 presidency is someone sensible and centrist,” Mr. Musk posted in November 2022, weeks after buying Twitter — and just as he brought Mr. Trump back onto the platform. He added that he had been hopeful about the Biden administration, but was “disappointed so far.”

In January, Mr. Musk ramped up his critiques of Mr. Biden. He posted seven times about the president that month, primarily regarding immigration policies, just as the Biden administration sued Texas over a law that allowed local law enforcement to arrest migrants.

“I cannot see myself voting for Biden,” Mr. Musk said, accusing the president of “facilitating illegal immigration.”

In February, Mr. Musk said Mr. Biden supported lax immigration restrictions because they would give him and the Democratic Party an advantage in the November election.

“Biden’s strategy is very simple: 1. Get as many illegals in the country as possible. 2. Legalize them to create a permanent majority — a one-party state,” Mr. Musk wrote. As the number of people crossing into the United States has reached record levels, Mr. Biden has called for a stricter crackdown on immigration and accused Republicans of stymieing his efforts.

Since then, Mr. Musk has escalated his commentary on Mr. Biden, posting 12 times in March and complaining the media is a “Biden cheering squad.”

Last month, at a dinner party in Los Angeles, Mr. Musk along with other billionaires, including Mr. Murdoch and the venture capitalist Peter Thiel, discussed how to oppose Mr. Biden’s re-election, according to a person familiar with the event, who spoke on the condition of anonymity to discuss sensitive matters. The dinner was earlier reported by Puck.

During an interview with the former CNN host Don Lemon in March, Mr. Musk said that he would continue voicing his opinion but didn’t want “to put a thumb on the scale monetarily that is significant,” and that he might endorse a candidate during “the final stretch.”

”I’m leaning away from Biden,” he said, laughing.