Independent presidential candidate Robert F. Kennedy Jr. sought a meeting last week with Democratic nominee Kamala Harris to discuss the possibility of serving in her administration, perhaps as a Cabinet secretary, if he throws his support behind her campaign and she wins, according to Kennedy campaign officials.

Harris and her advisers have not responded with an offer to meet or shown interest in the proposal, say people familiar with the conversations.

The Kennedy outreach, made through intermediaries, follows a meeting in Milwaukee last month between Kennedy and Republican nominee Donald Trump to discuss a similar policy role and endorsement that resulted in no agreement. In those discussions, Kennedy spoke about advising Trump in a second term on health and medical issues.

The independent candidate and namesake of the most famous American political dynasty is exploring multiple options for the future of his presidential effort, which has seen a decline in national polling since President Joe Biden dropped out of the race. His campaign has produced polling, which it has tried to share with Democrats, that it claims shows both Harris and Trump would get a boost in their public support across 31 states if either candidate announced publicly that Kennedy would have a Cabinet role in their administration.

At the moment, Kennedy says he is continuing to campaign with the expectation that he will defeat both Trump and Harris, making regular interview appearances, releasing an “America Strong” plan for bipartisan governance and planning upcoming rallies in states such as Arizona and Nebraska. But he has also left open the possibility of bowing out of the race if he finds another way to bring about the change he seeks in the country, his advisers say.

“From the beginning of this campaign, we were saying people should be talking to each other,” Kennedy said Wednesday in an interview. “That is the only way of unifying the country.”

Kennedy said he hopes Harris reconsiders his offer of a meeting. “I think it is a strategic mistake for them. That’s my perspective,” Kennedy said. “I think they ought to be looking at every opportunity. I think it is going to be a very close race.”

The latest round of outreach follows earlier efforts to convince Democrats that Kennedy would make a better candidate on their ticket than Biden. Even after Kennedy left the Democratic nomination fight to pursue an independent campaign for president last November, his advisers continued to press the case privately that he could replace Biden as the Democratic nominee.

Amaryllis Fox Kennedy, the campaign manager and daughter-in-law to the candidate, argued in an April email to Democrats, obtained by The Washington Post, that Biden could not win the race. “As things are, Biden is going to lose. If Bobby were to drop out, Trump would win by an additional two states,” she wrote. “If Biden were to drop out, Trump would lose. Only Bobby can win this.”

She argued that Democrats had to make sure a president is elected who could handle the responsibility of managing the nuclear arsenal. “I don’t want a president obsessed with the size of his crowds to be given that sacred charge. My bomb is bigger than your bomb is no path to peace,” she wrote. “Nor do I want to entrust my children’s lives to the alertness of a president who, despite honorable service and due to the natural toll of age, I wouldn’t leave babysitting my two-year-old while I went to the movies.”

Democrats have for months attacked Kennedy because Timothy Mellon, a scion of a Pittsburgh banking family, is a top donor to both an independent group supporting Kennedy and a separate group supporting Trump.

“No one has any intention of negotiating with a MAGA-funded fringe candidate who has sought out a job with Donald Trump in exchange for an endorsement,” said Lis Smith, an adviser to the Democratic National Committee.

Kennedy’s campaign reached out this summer to Democratic intermediaries, including Hollywood talent agent Ari Emanuel and director Rob Reiner, in hopes of starting a dialogue with Democratic officials, according to people familiar with the effort who spoke on the condition of anonymity to describe private conversations. No meetings resulted. Representatives for Emanuel and Reiner did not respond to requests for comment.

One day after Biden had a disastrous performance in a June debate with Trump, Kennedy campaign staff contacted a relative of Airbnb founder Joe Gebbia in an effort to get a message to Ron Klain, a longtime Biden adviser who had recently been hired by Airbnb as chief legal adviser.

“The Dems should nominate Kennedy. He is the only candidate under consideration who can beat Trump,” the message read, according to a copy obtained by The Post. “Please give it some thought. Kennedy would win, the Dems would keep the White House, and Americans would avoid the Trump reprise that so many across this nation dread.”

Klain said in a text message Wednesday that he heard secondhand that the Kennedy campaign was trying to reach him, but that he did not respond to the request.

A person who spoke on the condition of anonymity to describe the interaction spotted Kennedy at a hotel this week in West Palm Beach, Fla., not far from Trump campaign headquarters and Trump’s Florida home. Kennedy, in the interview Wednesday, declined to comment on whether he was in West Palm Beach or whether he has continued conversations with the Trump campaign.

Trump campaign advisers, who also spoke on the condition of anonymity to describe private conversations, said they are still in touch with Kennedy and his senior team, and some of the advisers are expecting Kennedy to drop out and endorse Trump. In his pitch to Trump in Milwaukee, he also discussed a Cabinet-level job.

Since Biden exited the race in July, Kennedy’s standing in national polls appears to have declined, suggesting that Harris has been able to attract some of his previous supporters. A Post average of national polls in July when Biden was still in the race showed Kennedy polling at about 9 percent. Since Biden dropped out of the race, the same average shows Kennedy polling at about 5 percent nationally.

Kennedy campaign officials believe that overall he is pulling support disproportionately from Trump at this point in the race, though there are state-by-state variations. Even if Kennedy did withdraw from the race and endorse one of the two candidates, his campaign believes there are states where he would not be able to remove his name from the ballot. Early voting in some states begins next month.

Kennedy said Wednesday that he had not had any contact with the Democratic Party since launching his campaign. The Democratic National Committee has launched an aggressive legal and political effort to diminish the appeal of Kennedy and other third-party contenders.

“The only contact I have with the DNC is them suing me through intermediaries,” Kennedy said.