The dueling appearances are a chance for each candidate to frame the stakes of the race as it plunges into uncharted territory, with Trump no longer running against his ideal opponent and Harris seeking to take charge of the Democratic ticket a little more than 100 days before the election. Democrats are hoping that Harris can refocus the contest on Trump’s flaws, while Republicans want to quickly define Harris and saddle her with Biden’s weaknesses.

Biden’s exit — triggered by a dismal June debate performance — has filled Democrats with new hope for November. In a Wednesday morning memo, Harris campaign chair Jen O’Malley Dillon said the vice president is less known than Trump and Biden and “opens up additional persuadable voters,” especially in groups that lean Democratic. “This race is more fluid now,” she wrote.

Trump’s team, meanwhile, is bracing for a “Harris honeymoon” that it says could intrude on Trump’s summer of momentum and polling gains. In a Tuesday memo, Trump pollster Tony Fabrizio predicted that Harris would see a polling bump starting in the next few days — but he said it would pass. With voters upset about inflation, the border and other issues, he wrote, the “fundamentals of the race stay the same.”

Harris plans to arrive in Indianapolis just after noon on Wednesday and deliver a keynote speech there at the Grand Boulé, the national convention of the Zeta Phi Beta sorority. Zeta Beta Phi is one of the “Divine Nine,” a group of historically Black sororities and fraternities that includes Harris’s sorority, Alpha Kappa Alpha.

Democrats are hopeful that Harris — who is Black and Indian American and would be the first female president — can motivate key left-leaning constituencies in a way that Biden did not. In interviews, Black women gathered for the Grand Boulé said they were excited about Harris’s candidacy but also nervous about her chances. They worried that voters would hold her race and gender against her.

“If you had your eyes closed and you just go based on her qualifications versus [Trump’s] qualifications, yes, she’d definitely win,” said Lora Rice, 55, from Georgia. “But they’re not going to do that.” She said Biden, “the White guy,” would have had a better shot.

Democratic leaders and delegates to next month’s nominating convention have quickly rallied behind Harris. Former secretary of state Hillary Clinton, who made history as the country’s only female presidential nominee from a major party, voiced support for Harris in a New York Times op-ed published Wednesday.

“I know a thing or two about how hard it can be for strong women candidates to fight through the sexism and double standards of American politics,” wrote Clinton, who lost to Trump in 2016. She warned that Harris’s “record and character will be distorted and disparaged” as she runs against Trump, and that “she and the campaign will have to cut through the noise.”

In her memo, O’Malley Dillon laid out her case for confidence in Harris. She led the charge on abortion rights, an issue on which Democrats have demonstrated a clear political advantage. In Milwaukee on Tuesday, she drew the campaign’s largest crowd to date. Some $126 million in donations have flooded into the campaign since Sunday, when Biden dropped out and endorsed Harris.

O’Malley Dillon said the campaign would continue its focus on the so-called “Blue Wall” states — Michigan, Wisconsin and Pennsylvania — as well as the “Sun Belt” battlegrounds of Arizona, Georgia, Nevada and North Carolina. “We intend to play offense in each of these states, and have the resources and campaign infrastructure to do so,” she wrote.

Biden, before he dropped out, had increasingly looked to the Blue Wall as his path to victory — as other states slipped further from his grasp and as Trump threatened to put Democrats on defense in traditionally blue states. And Trump’s campaign is still trying to expand the map: The former president has another rally planned for Saturday evening in Minnesota, a state that Biden won by seven points in 2020.

Even as Trump’s campaign pivots to attacking Harris, the former president has tried keep attention on Biden.

“Does Lyin’ Kamala Harris think Joe Biden is fit to run the U.S.A. for the next six months? She must answer the question,” Trump wrote on Truth Social, his social media site, on Tuesday.

Biden is scheduled to give a speech Wednesday night from the White House about his decision to bow out, which came after weeks of pressure from other Democratic leaders and a debate in which Biden repeatedly appeared to lose his train of thought.

Harris heads to Houston on Wednesday after the sorority event. Trump’s team, eager to needle Harris about immigration policy, quickly highlighted her planned proximity to the southern border.

Trump has several events lined up later this week. He plans to speak Friday evening in West Palm Beach, Fla., at an event hosted by the conservative group Turning Point Action. On Saturday, he will deliver a keynote speech at the Bitcoin Conference in Nashville, underscoring his newfound interest in cryptocurrency. Trump was once skeptical of cryptocurrency but has embraced it after aggressive lobbying by executives in the industry.

Sabrina Rodriguez in Indianapolis contributed to this report.