DENVER -- From somewhere in the luncheon crowd, chants of "four more years" break out as Bill Clinton is introduced.
Clinton isn't running for office, but he might well be in the early phase of a White House comeback try unlike any other.
Public approval for the way he handled his job as president has increased significantly in recent years, even among Republicans. A USA Today/Gallup poll this month put his job approval rating as president at 61 percent. (President Bush's was 36 percent in the same survey.)
Clinton is generating considerable buzz among party insiders as he tours the country, raising millions for Democrats and renewing contacts that could pay off handsomely for his wife, Sen. Hillary Rodham Clinton, if, as expected, she runs for president.
For some voters, the prospect of sending Bill Clinton back to Washington, whether in a formal position or as a behind-the-scenes adviser, could be an asset for his wife's candidacy, Democrats say. But exactly what role he would play in her campaign, and in her administration if they returned to the White House, poses a complicated set of issues.
"On the one hand, [Bill Clinton] is a peerless political strategist with pretty close to perfect pitch," said Bill Galston, who was White House domestic policy director in Bill Clinton's first term. "On the other hand, it's extremely important for her to run her own campaign and to be seen as doing so. And those two large facts are in some tension with each other."
Nonetheless, Bill Clinton remains his wife's most important adviser.
"She talks to him multiple times a day, and she bounces most of the stuff off him," said Terry McAuliffe, who is very close to the Clintons.
Representatives of Hillary Clinton, who faces token opposition in her New York re-election contest this fall, would prefer to keep details of her husband's involvement quiet.
"That's not something we talk about," said Howard Wolfson, a key adviser to the senator, when asked whether the former president sits in on her strategy sessions. "It's fair to say that he is invested in and involved with her candidacy in the way that you would expect any spouse to be engaged in the campaign of the candidate."
McAuliffe, who was Bill Clinton's chief campaign fundraiser and later served as national Democratic chairman, said the former president participates in formal meetings of his wife's campaign organization rarely, "maybe once or twice a year."
For his part, Clinton says that if his wife becomes president, "I'll do whatever she wants," as he put it in response to an audience question recently in Little Rock, Ark.
For now, the Clintons maintain largely separate public schedules, avoiding side-by-side comparisons like the one at Coretta Scott King's funeral last winter, which can work to Hillary Clinton's disadvantage. But the former president rarely misses an opportunity to promote his wife.
Though he says he doesn't know whether she'll run, he told an Israeli TV station last fall that she would be a better president than he was in some ways because of her Senate experience and the eight years they spent in the White House. More recently, during a hectic, campaign-style day of events in Denver, he managed to put in a plug for her at every stop.
Clinton, the youngest former president in history when he left office, turns 60 this summer. After a slow recovery from heart surgery 18 months ago, he appears to be back in top form. His popularity is surging, whether out of nostalgia for the 1990s, contrasts with Bush or simply the passage of time.
Clinton says that the constitutional amendment that keeps him from seeking a third term has freed him to speak his mind.
"As long as I don't hurt Hillary, I don't care what they say about me," he likes to say.
His far-flung activities are an unusual blend of Jimmy Carter-like good works on a global scale combined with a seemingly nonstop speaking schedule, sometimes for eye-popping fees (about $150,000 an hour, for a total of $7.5 million last year, according to Hillary Clinton's latest financial disclosure report).
Occasionally, the Clintons seem to be in conflict. Last winter, Bill Clinton denied news reports that he had attempted to help the government of Dubai gain approval of an unpopular U.S. port deal that his wife strongly opposed. But he acknowledged that he had given Dubai advice, including ways it might try to counter the storm of opposition in Washington, while publicly endorsing his wife's efforts to require American ownership of U.S. port operations.
More often, the Clintons are in sync. Their speeches echo many of the same priorities. Both are emphasizing the need to end America's longtime dependence on imported oil, an issue on which he devoted relatively little effort during his presidency.
Both Clintons are also going to considerable lengths to distance themselves from the Washington partisanship that voters say they strongly dislike. After raising more than $200,000 for Maine Democrats this month, Bill Clinton spent the evening with former President George H.W. Bush, in his second visit in a year to the seaside home of the one-time foe he now calls "my partner." In public appearances, Bill Clinton often points out that his wife is co-sponsoring health care legislation with Senate Republican leader Bill Frist and that her concern over climate change took her to Norway with Republican Sen. John McCain.
Their most notable policy difference, over the Iraq war, enables the Clintons to span a broad expanse of public opinion on the most important issue in the country. His criticism of the invasion as a "big mistake" is more in line with the views of his party's liberal base. Hillary Clinton, who voted to authorize the use of force, was booed at a liberal gathering this month when she said it would not be a smart strategy to fix a firm date for a U.S. withdrawal.
During Bill Clinton's first presidential campaign, when his wife's professional background made her a new kind of political spouse, the couple tried to capitalize by offering a voters a deal: "Buy one, get one free." That slogan was quickly abandoned after Republicans raised the specter of a "co-presidency" that would unleash her liberal ideas on the nation.
If she runs in 2008, a different dynamic, which has pushed the former president into the background of his wife's career, would likely govern his involvement, at least publicly. Clinton insiders are trying to discourage the notion that he would play a central part in a third Clinton administration.
"He wouldn't want any of that. He had his eight years," McAuliffe said, speculating that Clinton would serve as a roving "ambassador of goodwill" if his wife became president.
Democratic activists, including some who paid $500 to hear him speak in Denver, say they're aware that Bill Clinton is tailoring his activities to help his wife's presidential chances.
"I think he's kind of walking softly because he doesn't want to [mess] up his wife's thing," said Sam Sussman, in his mid-50s and owner of a Boulder, Colo., copy shop. "Bill knows how to tiptoe around, doesn't he?"
Bill Clinton enjoys near-total popularity among Democrats nationwide (91 percent approve of the job he did as president, according to this month's poll). But some aren't sure they want the man who once called himself "the Comeback Kid" to try to return to power as first man.
"I wish he could run again," said Mark Davis, 48, of Vail, Colo., who also said he hopes that Hillary Clinton won't. "She's too much of a lightning rod. I think the Republicans would love to run against her. It would be about her, and it would be about Bill. Probably my biggest concern with her running is regurgitating the '90s again. The '90s were tough on her and on Clinton, and I don't think that's what 2008 ought to be about."