In his remarks, Senate Majority Leader Chuck Schumer praised Vice President Harris and said she will need a Democratic majority if she wins the presidency.

"She can't do it alone," he said.

Schumer predicted Democrats will perform well this November, calling back to the "red wave" prediction that didn't materialize in 2022 and listing candidates he said are strong in closely-watched races in Montana, Arizona and Maryland.

"Ladies and gentlemen, my good friends at this convention: I am telling all of you now we're going to hold the Senate again and we're poised to pick up seats," he said.

Schumer served alongside Harris in the Senate.

Behind Enemy Lines, a pro-Palestinian group, gathered early evening Tuesday in front of the Consulate of Israel in downtown Chicago.

Initially there was a small group of about 25 people, but the numbers grew within an hour -- enough for police in riot gear to hold a formation to prevent the group from moving farther down the block.

Behind the police line stood a pro-Israel group of about 100 demonstrators holding flags. Both groups were aware of the other and, at one point, each pressed against the police line from both sides.

No clashes took place.

Around 8 p.m. local time, the Israel group started dispersing.

At least five people were seen being taken into custody. The police didn't initially report any arrests.

Chicago Police Superintendent Larry Snelling was seen standing among the officers.

-ABC News' Mark Guarino

Harris addressed the DNC crowd from a rally in Milwaukee and thanked the delegates for nominating her as the Democratic presidential nominee.

Harris spoke at the Fiserv Forum, where Trump accepted the nomination last month.

"This is a people-powered campaign, and together we will chart a new way forward," she said.

Read more about the Harris campaign's decision to hold a rally in the battleground state of Wisconsin on the same night as the DNC here.

California, Harris' home state, delivered the delegates to send Harris over the top during the ceremonial roll call.

Gov. Gavin Newsom announced that the state is casting its 482 votes for Harris, whom he called a "bright star" whose star has gotten even brighter as she served as the state's attorney general, a U.S. senator and now as vice president.

"Kamala Harris has always done the right thing, a champion for voting rights, civil rights, LGBTQ rights," Newsom said. "It's time for us to do the right thing -- and that is to elect Kamala Harris as the next president of the United States of America."

Harris is already officially the nominee after the DNC held a virtual roll call earlier this month. Still, the symbolism, and the relationship between Newsom and Harris, is significant.