Organizers at Bill Clinton's final, glittery gathering of his family's philanthropic organization seem determined to keep his wife's presidential prospects off the agenda.

Hillary Clinton's image was notably absent from the gauzy video that kicked off the last-ever meeting of the Clinton Global Initiative. Contributors at Monday's opening session thanked President Clinton and daughter Chelsea for their work, but skipped over the Democratic nominee.

Finally, Italian Prime Minister Matteo Renzi broke the ice.

Noting that he'll be hosting one of the first international summits after the U.S. election, Renzi turned to President Clinton and said with a smile, "My wife waits for you as first gentleman at the G-7."

That easy mingling of philanthropy and politics has put the Clintons' charity work under an election year microscope. Republican Donald Trump contends the Clinton Foundation is little more than a way for his opponent to enrich her family and give donors special political access. Even some Clinton supporters have questioned the necessity of keeping the foundation afloat given that she is already saddled with questions about transparency.

The Clintons have vigorously denied that they have personally profited from the foundation or given financial backers unique access to Hillary Clinton as secretary of state.

"Nobody in my family ever took a penny out of this foundation and put millions of dollars in -- but I would have paid more to do this job," Bill Clinton said in an interview with NPR that aired Monday. "It was the most fun thing I think I've ever done."

Still, in an attempt to quiet the doubters, Bill Clinton announced earlier this year that he would step down from the foundation board if his wife wins in November, a move he told staffers would be as painful as a "root canal." He also announced that 2016 would be the last CGI meeting, regardless of the election's outcome.

Some donors chose to stay away from this week's gathering, a decision some privately suggested was less about election year politics and more a reflection of having moved on now that the initiative is winding down.

Still, the crowd gathered in the ballroom of a midtown Manhattan hotel reflected Bill Clinton's unique ability to draw from all corners of influence.

Former Secretary of State Madeline Albright moderated a panel that included both musician Bono and retired Marine Gen. John Allen. A celebratory dinner was honoring singer Jon Bon Jovi and Nadia Murad, a Yazidi human rights activist.  Renzi appeared on a panel along with new Argentinian President Mauricio Macri and London Mayor Sadiq Khan.

The eclectic headliners also underscored the overlap between the Clinton's charitable work and political ambitions.

Albright is an ardent Clinton supporter. Allen vouched for her national security experience during an impassioned address at this summer's Democratic convention. Bon Jovi performed at a Clinton fundraiser in the Hamptons in August. And Khan voiced his support for Clinton's candidacy last week.

The London mayor also dipped his toe in the U.S. elections during his remarks Monday, taking a veiled jab at Trump, who has called for a temporary ban on Muslims coming to the U.S. During his appearance alongside Bill Clinton, he said, "I say to those -- you may know who I'm talking about -- there is nothing incompatible with having Western liberal values and being a mainstream Muslim."

The vast majority of the three-day gathering is centered on the Clinton Foundation's wide-ranging projects around the world. Among them: boosting the availability of life-saving HIV drugs, expanding access to clean drinking water, and stopping elephant poaching in Africa, a particular passion of Chelsea Clinton's.

Supporters of the foundation say its work has been unnecessarily obscured by presidential politics.

"The value has been substantial," said Rev. Jesse Jackson, the civil rights activist and longtime CGI participant. "It was not an issue until Hillary became this close to being president."

Neal Keny-Guyer, the CEO of the global humanitarian organization Mercy Corps, was among a small group of longtime CGI participants who attended a private reception with Bill Clinton on the eve of the final meetings.

"I'm not sure it's sunk in that it's the last year," he said.

Keny-Guyer described the former president as wistful and sentimental as he prepares to potentially step away from the foundation that has been the cornerstone of his post-White House legacy. But he said participants were sure to not bring up what comes next.

"I think all of us are sensitive to that," he said.