What to Know About Night 3 of The Democratic National Convention

After two nights of preliminary revels that laid out Joseph R. Biden Jr.’s biography and the values of his party, the Democratic Party turns on Wednesday to forging its ticket in earnest. Senator Kamala Harris, the vice-presidential nominee, is the headline speaker of the night, giving remarks that will introduce her to a national electorate that still only has a modest familiarity with her political identity and ideas.

It is a crucial speech not only for Ms. Harris but for the whole Democratic general-election effort. It will be the first opportunity for Americans to hear from someone who is actually asking for their vote on the national ballot about what a Biden-Harris administration aims to achieve. With a few exceptions so far — including Senators Bernie Sanders and Chuck Schumer — Democrats have not gone into much detail about how a government led by their party would change the lives of ordinary people.

But Ms. Harris will not have to fill in those blanks by herself. Two of her party’s best-known leaders, and most fluent policy representatives, will be speaking before her: former President Barack Obama and Senator Elizabeth Warren. Both have leaned hard into a message of sweeping economic and social change — Ms. Warren during her presidential bid, Mr. Obama in a number of recent public remarks — and they are likely to help the party clarify its governing aims in a way it has not yet done this week.

Kerry Washington, who recently received four Emmy nominations, follows in the footsteps of Eva Longoria and Tracee Ellis Ross as tonight’s M.C.

  • Hillary Clinton, the 2016 Democratic nominee and former secretary of state. Four years ago, she appeared onscreen to the sound of breaking glass before being nominated herself. This time, she will be speaking on behalf of the man she hopes can beat Mr. Trump where she could not.

  • Gov. Tony Evers of Wisconsin, the nominal home of the convention. He narrowly defeated Scott Walker, the Republican incumbent, for the governorship in 2018, two years after Mr. Trump won the state.

  • Former Representative Gabrielle Giffords of Arizona. Almost killed in a mass shooting in 2011, she has since become one of the United States’ most vocal advocates for stricter gun laws, and her husband, Mark Kelly, is the Democratic candidate for Senate in Arizona.

  • Senator Kamala Harris of California, Mr. Biden’s running mate. She is the first woman of color on a major party’s presidential ticket and will be looking to energize Black voters, the Democratic Party’s most loyal constituency.

  • Gov. Michelle Lujan Grisham of New Mexico. She is the first Latina Democrat to lead any state and was a vice-presidential contender, and like several other governors, she received some national attention for her response to the coronavirus pandemic.

  • Former President Barack Obama. More than anyone else in the Democratic Party, he is seen as a potential uniter of the party’s moderate and progressive factions. He did not weigh in publicly while the primary was competitive, but he has become more active on the campaign trail (or what remains of it) since endorsing Mr. Biden in April.

  • Speaker Nancy Pelosi, the House Democratic leader. She has been on the front lines of the ongoing legislative fights with the Trump administration over coronavirus relief and funding for the United States Postal Service.

  • Senator Elizabeth Warren of Massachusetts. She and Senator Bernie Sanders, who spoke on Monday, were the two most prominent progressive candidates in the Democratic primary, and she was on Mr. Biden’s vice-presidential shortlist.