Robert F. Kennedy Jr. has officially withdrawn his petition to be on the Arizona ballot, the secretary of state's office told ABC News Thursday night, the first tangible sign he plans to exit the presidential race.

"We have processed withdrawal forms for RFK prior to the ballot printing deadline. No changes may be made to put the electors back on the ballot now," Arizona Secretary of State Spokesman JP Martin said.

ABC News' Will McDuffie

Former President Donald Trump told Fox and Friends Thursday morning that he would be "honored" to receive Robert F. Kennedy Jr.'s endorsement.

ABC News previously reported that RFK Jr. is expected to drop out of the presidential race by the end of the week.

"I've known him for a long time. He's, as you know, he's a little different kind of a guy, very smart guy, a very good person. If he endorsed me, I would be honored by it. I would be very honored by it," Trump said. "He really has his heart in the right place. He is a respected person. Women love some of his policies, and I guess some people don't like some of his policies."

-ABC News' Kelsey Walsh

Four Illinois voters sat down with ABC News at the start of the Democratic National Convention to discuss Biden's bombshell decision, the rise of Harris as the party's nominee and her possible historic path to the presidency.

Edgar Diaz, a 43-year-old moderate Democrat who lives in Chicago, told ABC News he was relieved when President Joe Biden stepped aside. "I think he's realized that, 'Hey, you know what? Now it's time to step aside and let somebody like Kamala Harris step in,’” he said.

Grace Walters, 25, said she was encouraged by the energy around the vice president’s campaign. “It became less about vote for us because we're not them, and more vote for us because we're doing X, Y and Z -- and that is always an easier thing to get behind,” she said.

But David Spada, a 53-year-old conservative Republican, asked those planning to back the Democrats whether they were concerned that voters did not get to choose their own candidate.

"Shouldn't the voters pick who the candidate is for president, not just the party?" Spada asked.

-ABC News’ Alexandra Hutzler

Vice President Kamala Harris is setting out to achieve three key objectives in her highly anticipated Democratic National Convention speech Thursday night, according to a campaign official.

Harris intends to highlight her background -- she was raised by a working mother in a middle-class neighborhood -- to show she shares the experiences, challenges, and values of middle-class families.

She will also detail her journey to becoming a prosecutor in order to protect others -- like survivors of sexual abuse or homeowners impacted by the foreclosure crisis -- a campaign official told ABC News.

Harris will then set out the dangers posed by former President Donald Trump's campaign, specifically, the Project 2025 agenda. The vice president will look to contrast that with her “New Way Forward” agenda, the campaign official said.

-ABC News’ Gabriella Abdul-Hakim, Will McDuffie, and Fritz Farrow