WASHINGTON— Once a tense rivalry, the relationship between President Barack Obama and Bill and Hillary Clinton has evolved into a genuine political and policy partnership. Both sides have a strong incentive in making the alliance work, especially in an election year.

For Obama, Bill Clinton is a fundraising juggernaut, a reminder that a Democrat ran the White House the last time the economy was thriving. For the spotlight-loving ex-president, stronger ties with the White House and campaign headquarters mean he gets a hand in shaping the future of the party he led for nearly a decade.

Obama’s campaign has put Bill Clinton on notice that he will be used as a top surrogate, further evidence of how far the two camps have come since the days of the 2008 Democratic primary between Obama and Hillary Clinton, now his secretary of state.

The 44th and 42nd presidents teamed up to address supporters in Virginia on Sunday night, the first of three joint appearances at fundraisers for Obama’s campaign. The Obama campaign expected more than 500 people at a reception at the home of Terry McAuliffe, a close adviser to both Clintons and one of the most ardent protectors of their political brand, with tickets starting at $1,000. Eighty people paid $20,000 each for dinner afterward.

Clinton told the crowd that Obama is “beating the clock” to restore the economy to health. Digging out of similar financial holes has taken five to 10 years, he said.

“Barack Obama deserves to be re-elected president of the United States,” Clinton said, because he has clear objectives for the country and is meeting them.

Neither Clinton nor Obama mentioned presumed Republican nominee Mitt Romney by name, but both zinged Romney for his economic plan and foreign policy credentials.Romney “basically wants to do what they did before, on steroids,” Clinton said, “which will get you the same consequences you got before, on steroids.”

Obama and Bill Clinton appeared relaxed and cordial. Clinton guffawed when Obama made gentle fun of him, and himself, by noting every presidential candidate always says the next election is crucial.

Clinton’s willingness to be a good soldier for the Obama campaign could end up paying political dividends for his wife, who is frequently talked about in party circles as a potential presidential candidate in 2016 despite her repeated denials. Hillary Clinton’s popularity has skyrocketed during her time in Obama’s Cabinet.

“It makes absolutely clear that, to the extent that there were different wings of the Democratic Party, there is now one wing of the Democratic Party,” said Chris Lehane, a Clinton supporter. “And it’s the president’s party.”

---- Discussions are under way at Romney’s Boston headquarters about the degree to which Bush will participate, if at all, in the general election. Many Republicans are reluctant to publicly associate with Bush, who left office deeply unpopular, especially as the Obama campaign seeks to tie Romney to Bush’s economic and foreign policy positions. ---- While Obama and the Clintons are rarely described as friends, people close to them say the relationship has warmed significantly since the 2008 nomination contest. In that race, the former president slammed Obama’s candidacy as a “fairy tale” while Obama sarcastically told Hillary Clinton that she was “likable enough.” ---- The thaw started as a matter of political necessity: Their party was desperate to retake the White House after eight years of Republican rule. Hillary Clinton offered Obama a gracious endorsement, both Clintons campaigned for Obama, and the newly elected president picked his former rival to be America’s chief diplomat. ---- It took longer for Obama’s relationship with Bill Clinton to soften as the two men found common ground in the pressures of the presidency. ---- When Obama’s health care bill was in trouble, he and his staff, which included several veterans of the Clinton White House, called on the former president for help. In late 2009 and early 2010, Bill Clinton went to Capitol Hill to rally support and worked the phones with wary Democratic lawmakers. ---- After the Democratic party was battered in the 2010 elections, Obama called in Clinton for an Oval Office meeting. Afterward, the two made an impromptu appearance in the White House briefing room to talk to reporters. When Obama had to leave for a holiday party, Clinton stuck around, relishing in the attention and the give-and-take with the press. ---- That day in the briefing room underscored what some Democrats see as their one major worry in pairing Obama with Clinton too often. The ease with which Clinton connects with a range of audiences can call attention to the challenge Obama sometimes faces in doing the same thing. ---- But that certainly hasn’t stopped the Obama campaign from seeking Clinton’s help in winning a second term, and Clinton has made it clear he is ready and willing. ---- Obama’s campaign advisers have sat down with Clinton for strategy and advice-seeking sessions, and the former president had a prominent role in movie produced by the campaign in which he promoted, among other things, Obama’s decision to order the raid that killed Osama bin Laden. ---- “There is no better Democratic ally than President Clinton,” said Jim Messina, Obama’s campaign manager. ---- Follow Julie Pace at http://twitter.com/jpaceDC