Former US President Bill Clinton has made his first major appearance alongside his wife, Hillary, as she campaigns in the 2008 White House race.
Mr Clinton urged the Democratic faithful to support his wife
The couple took to the stage in Iowa, a crucial state because it is among the first to pick which candidate from each party will run for president.
Mr Clinton said his wife was the "best qualified non-incumbent I have ever had a chance to vote for president".
Mrs Clinton is trailing Democratic rival Barack Obama in fundraising.
Until now, former President Clinton has largely concentrated on fundraising for his wife and they have made few public appearances together.
Later in July they are due to travel to New Hampshire, another key early state.
At a rally in Des Moines on Monday night, Mr Clinton praised his wife and urged the Democratic party faithful to support her.
"You will never have anybody in the White House who cares more about how every decision she makes affects you," he said.
"I'd be here tonight - if she asked me - if we weren't married."
Taking the stage after her husband's introduction, Mrs Clinton joked: "If I was as smart as Bill seems to suggest I am, I would say nothing."
The couple are due to travel to Iowa City on Tuesday and Clear Lake on Wednesday, where they will join a 4 July parade.
Mrs Clinton will then spend a fourth day campaigning in Iowa without her husband.
Their joint appearance has prompted questions about whether Mr Clinton's presence will remind voters of past scandals, such as his affair with White House intern Monica Lewinsky.
Commentators have also asked whether Mr Clinton's talents as a communicator mean he risks overshadowing his wife if they appear on the same stage.
A spokesman for Mrs Clinton's campaign team said her husband would concentrate on telling supporters about her background and her efforts to help women and children.
The New York senator has trailed her chief Democratic rivals, Mr Obama and former North Carolina Senator John Edwards, in some polls in the state.
Senator Obama's campaign team announced on Sunday he had raised $32.5m (£16.2m) in the second quarter of campaign fundraising, compared to some $27m (£13.5m) for Mrs Clinton.
Mr Edwards' campaign reported a second-quarter total of just over $9m (£4.5m).