– The convention the Republicans just wrapped up in Cleveland, with its prime-time plagiarism, backstabbing rivals and missing dignitaries, may not be a tough act to follow, but Democrats are nonetheless in a state of high anxiety as the spotlight shifts to them this week.

The party will stage its national convention in Philadelphia at a time Hillary Clinton would be breaking records for unlikability were she not outdone by Republican nominee Donald Trump. In addition to distrusting her, too many voters are not clear about what she stands for and question whether she can bring about the change they crave.

The convention is a crucial opportunity for Clinton to define herself as something beyond the anti-Trump.

But Clinton has strained for months to come up with an overarching message despite a website filled with policy plans and a scholar's grasp of almost every imaginable issue. Voters are more likely to know about her e-mail troubles and speeches to Goldman Sachs than her plans to boost the fortunes of the middle class. It's a reality Clinton's team has been struggling with in every stage of planning for the event.

"We will offer a very different vision," Clinton promised during a rally in Florida on Friday. "This is about building bridges, not walls. It is about the economy working for everyone, not just those at the top. It is about embracing the diversity that does make our country great."

The struggle to come up with a defining message is familiar for candidates trying to win a third consecutive election for their party. After two terms, voters almost always are in the mood for change, and addressing that hunger while defending the status quo is a tough assignment.

Some have succeeded: George H.W. Bush helped cement his eventual victory with a convention speech calling for a "kinder, gentler" nation. Al Gore could not pull it off.

Clinton's problems could be compounded if restive Bernie Sanders supporters protest loudly at the convention over Clinton's pick of a moderate establishment-type as her running mate — Sen. Tim Kaine of Virginia. They are also angry about internal Democratic National Committee e-mails published Friday by WikiLeaks that bolster assertions the Sanders campaign made during the primary season that the DNC was working to undermine it.

Despite Clinton being one of the best-known nominees in history, convention organizers say the average voter knows little about her upbringing, advocacy or public service accomplishments. They will, yet again, reintroduce Clinton to the world with a mix of expertly produced video, spirited addresses from high-powered surrogates and personal anecdotes delivered by Clinton and her family.

"When I first arrived in the Senate and people told me who to emulate, they told me to emulate Hillary Clinton — to put your head down, work hard," Sen. Cory Booker of New Jersey said in Cleveland last week, offering a preview of the kind of things that will be talked about at his own party's convention.

But at a time the electorate is looking for change, Clinton's biggest asset may still be her alliance with a president at the end of his second term. Obama's resurgent popularity and mastery of campaigning makes him a key player in the bid to boost Clinton's stock with voters this week.

White House officials have been heavily engaged in convention planning. The president's surging approval ratings come as a large swath of the electorate alarmed by Trump finds renewed appreciation of Obama.

In Philadelphia, Obama and other Democrats will define Clinton as a leader who is trustworthy, battle-tested and prepared to take over as commander in chief while stoking fears that Trump is erratic, divisive and self-absorbed.

But as Democrats prepare to meet, Clinton has yet to hit on a compelling, succinct message that resonates on the economy. Voters are tiring of hearing about the turnaround Democrats orchestrated after inheriting the 2007-09 recession, particularly as middle-class incomes stagnate. And despite all her multipoint plans, Clinton has not been as skilled as her husband at generating enthusiasm for such mundane matters. There is the danger that slogans about debt-free college, a $15 minimum wage and expanding the Affordable Care Act leave voters with a jumble rather than a unified economic theme.

Party leaders, though, say they are less worried about reinventing Clinton than reintroducing her and leaving voters with a clear impression of what she is offering that Trump is not.

U.S. Rep. Xavier Becerra, D-Calif., who has been helping lead the Clinton campaign's outreach to Latinos, summed up the task before Democrats in Philadelphia by quoting one of Vice President Joe Biden's favorite lines: Don't compare me to the almighty; compare me to the alternative.

"Hillary Clinton will tell you she has made mistakes," Becerra said. "She is not the almighty. But she is not the alternative."