WASHINGTON -- When Bill Clinton left the White House, he was popular but tainted by scandal. He eventually channeled his energy into the global philanthropy that bears his name and is shaping so much of his post-presidential legacy.

Now, he faces the prospect of walking away from the Clinton Foundation. He has promised to step down from the board if Hillary Clinton wins the White House in November, a commitment made amid swirling questions -- pushed along by Donald Trump -- about her ability to separate herself from the foundation's wealthy contributors at home and abroad.

For the Clintons, the decisions surrounding the foundation are the latest chapter in an unprecedented partnership of personal and political ambitions. While political spouses -- Hillary Clinton among them -- often put aside their own goals, never before has that been required of a former president.

Friends and associates say Bill Clinton has accepted that his role in the high-profile charity has to change. But he's also said to be deeply frustrated with the criticism that is shadowing his potential exit.

"We're trying to do good things. If there's something wrong with creating jobs and saving lives, I don't know what it is," he said last week.

Mark Updegrove, the director of the Lyndon B. Johnson presidential library and author of Second Acts: Presidential Lives and Legacies After the White House, said that while the foundation has unquestionably done good work around the world, the president has no choice but to step aside if his wife wins the White House.

"Bill Clinton is smart enough to know that as much as the Clinton Foundation might help to augment his legacy, Hillary Clinton becoming president will be a far greater legacy than anything he himself can do as a former president," Updegrove said.

The foundation made some adjustments after she became secretary of state, but it has still faced numerous questions about how rigorously firewalls, which were meant to separate donors from her government work, were upheld.

An Associated Press review of Clinton's calendars from a two-year stretch show that more than half of those she met with from outside of government had made contributions to the foundation.

Meanwhile, there's a unique reality of modern U.S. politics: What presidents do after leaving the White House can shape their legacy almost as much as their tenure in the Oval Office.

It can be an opportunity to bolster presidential successes and try to make up for failures. And those who leave office relatively young -- Clinton was 54 -- can spend many more years on these legacy projects than they did in the White House.

Jimmy Carter, who was seen by some as an ineffectual one-term president, has dramatically reshaped his image with decades of work on global issues. George W. Bush left office deeply unpopular but has been applauded for dedicating his post-White House years to HIV programs in Africa and work with wounded military veterans. President Barack Obama has been discussing plans for his White House afterlife with confidants for months.

"There's a certain expectation that you stay involved, you don't totally get off the scene," said Anita McBride, a longtime Bush family aide.

Bill Clinton's foundation began largely to support the building of his presidential library in Little Rock. As his post-White House ambitions grew, so did the foundation, ballooning into a $2 billion charity focused on global health, climate change and other international efforts.

The former president has played an active role, leveraging his contacts to fill the foundation's chest and traveling around the world to meet with people helped by its work. He's the star of the annual Clinton Global Initiative meetings in New York, a mingling of international power players and celebrities that has become the hottest invitation in the philanthropic community.

"The work of the foundation is as important to him as anything he's ever done in a lifetime of public service," said Matt McKenna, who worked as Clinton's spokesman until last year.

The Clintons waited until this month to announce a blueprint for the foundation's future in the event Hillary Clinton wins in November. The plan involves the former president stepping down from the board, though daughter Chelsea Clinton will remain. Foreign and corporate donations will be halted, though the foundation is looking for ways to spin off some programs to keep them running.

The prospect of Bill Clinton stepping away from the foundation that has been the main outlet for his energy and intellect has renewed discussions about how he would fill his time in his wife's administration. Though he's now 70 and slowed by health issues, people close to the Clintons say they fully expect him to seek a prominent role.

"He just has to feel productive every single day," said Susie Tompkins Buell, a longtime Clinton friend. "If he gets into another situation where he's going to have that ability, he's going to be fine."

A Section on 08/31/2016