PHILADELPHIA — After Donald Trump presented a dark picture of the country at his convention in Cleveland last week, Hillary Clinton and the Democrats plan to project a more optimistic and inclusive vision of the future when they convene here starting Monday.

But the challenge for Clinton and her newly minted running mate, Sen. Tim Kaine of Virginia will be to avoid becomingcheerleaders for the status quo and instead infuse that hopeful tone into an argument for change that could galvanize a frustrated and divided electorate.

Democrats promise four nights of speeches and entertainment that will highlight the core theme of Clinton’s campaign: “Stronger together.” The program will alternate among political heavyweights led by President Obama and former president Bill Clinton, celebrities such as Katy Perry and Lena Dunham, and everyday Americans whose aim will be to make Clinton appear more appealing and approachable.

Clinton’s advisers are confident that the Philadelphia festivities will present a far more united Democratic Party than Republicans were able to display at their convention, which was repeatedly marred by outbursts of dissent and division.

Central to that mission is the Monday night speech by Sen. Bernie Sanders, Vt., who is charged with trying to rally his fervent supporters behind Clinton’s banner after a bruising primary battle, although there is lingering resistance to Clinton among some of his loyalists.

The harsh tone of Trump’s convention – symbolized by the anti-Clinton chants of “Lock her up!” – gives the Democratic nominee-in-waiting and her allies an opportunity to expand her appeal to disaffected voters who are hungry for change but perhaps reluctant to embrace Trump and the brand of politics he annunciated in Cleveland. At the same time, the Democrats similarly risk overreach in their denunciations of Trump.

Another danger is that if protests outside the arena turn violent, it could mar the party’s effort to provide a united and relatively peaceful contrast to the Republican event.

“The Republicans painted a black canvas with maybe a little stripe of red, which would be Donald Trump’s tie,” Democratic pollster Peter Hart said. “Unexpectedly, the Democrats end up with a white canvas and a chance to paint it in any direction that they wish.”

All year, Clinton has struggled to find a message that both energizes the Democratic faithful and reaches to a different part of the general electorate disenchanted with politics as usual. This will be her challenge on Thursday night, when she becomes the first woman to accept the presidential nomination of a major party.

“If she is so concerned about the progressive revolt that days one, two, three and four of the convention are saying, ‘I’m Bernie Sanders Lite with pantsuits,’ then this whole group turned off by Trump has nowhere to go,” said Henry Olsen, a fellow at the Ethics and Public Policy Center.

But Housing Secretary Julián Castro, who was in the competition to become Clinton’s running mate, noted the importance of energizing the coalition that helped Obama win two elections.

“We need an infusion of motivation and energy to remind folks that we can’t take this election for granted,” he said. “The nature of modern presidential elections, given the country’s partisanship, is that these are close elections. It’s probably not going to be a blowout, and people need to understand how important their individual vote is.”

Four days of programming at the Wells Fargo Center will showcase the Democratic Party’s diversity and progressivism, designed to help as many voters as possible identify with Clinton and the rest of the ticket. The speakers will be white, black, Latino and Asian; Christian, Jewish and Muslim; old and young; gay and straight; male and female. There is expected to be a heavy focus on such issues as immigration, gay rights and gun control.

Having watched the Republicans fight among themselves in Cleveland, Democrats will arrive in Philadelphia full of confidence. But some in the party suggest that, like much about Trump over the past year, what looks to be a problem for him does not always become one.

“We need to be agnostic on just how negative its consequences will be or indeed whether they’ll be negative at all,” said William Galston, domestic policy adviser in Bill Clinton’s White House and now a senior fellow at the Brookings Institution.

Whit Ayres, a Republican pollster, said, “If she lets this election get defined as change versus status quo, where Trump’s change and she is not, that’s one way she can lose this thing.”