(AP) -- A glass ceiling is shattering at the Democratic National Convention as Hillary Clinton ascends to the presidential nomination with Tuesday's roll call of the states, the first woman to lead a major party into a White House race.

Clinton's campaign hopes to use the achievement to bolster her popularity -- mindful that while many voters are happy to be nominating a woman, they're not wild about this particular one. Former President Bill Clinton, a string of celebrities and other speakers will offer prime-time testimonials to her career highlights and advocacy efforts, hoping to soften her image and resistance to her campaign.

As history is being made, hostility is being heard, too. Bernie Sanders' primary challenge has unleashed supporters' vitriol toward the party establishment that Sanders himself has been unable to rein in. His backers, many new to party politics, spent much of Monday protesting his treatment by top officials, even booing Clinton's name and, later, Sanders himself as he appealed for unity.

The division leaves what was once expected to be a tightly orchestrated convention, run with all the professionalism and experience that were lacking at the Republicans' often-chaotic coronation of Donald Trump last week, showing rough edges in the early going.

On Tuesday, Sanders, who has endorsed Clinton, tried to keep the conflict from consuming another day. This is an "unbelievably critical moment" for Democrats, he told Wisconsin delegates.

First lady Michelle Obama delivered the same message Monday night in a heartfelt endorsement of the candidate who engaged her husband in a fierce struggle for the nomination in 2008.

While Mrs. Obama has often avoided overt politics, she did not shy away from taking on Trump. Without naming him, she warned that the White House couldn't be in the hands of someone with "a thin skin or a tendency to lash out" or someone who tells voters the country can be great again. "This right now, is the greatest country on earth," she said.

Liberal favorite Elizabeth Warren, senator from Massachusetts, and Sanders himself also did their part to bring along his fans, some of whom were in tears by the time the Vermont senator took the stage to shouts of "We love you, Bernie."

But many protesters outside the Wells Fargo Center were unmoved. Chanting "Bernie or bust!," several hundred gathered in downtown Philadelphia for a 4-mile march to the convention hall. They decried police brutality, economic injustice and what some said was Clinton's greased path to victory.

Sanders "persuaded no one to vote for Hillary," said Greg Gregg, a retired 69-year-old nurse from Salem, Oregon, who said he intends to vote for Green Party candidate Jill Stein.

Trump cheered the disruption from the campaign trail. In North Carolina on Tuesday, he told a convention of the Veterans of Foreign Wars that, "our politicians have totally failed you."

When Trump mentioned Clinton's name, the group answered with shouts of "Lock her up!" an echo of the chants at last week's Republican convention. Clinton addressed the same group Monday. "I guess she didn't do very well," Trump said.

Clinton was firmly on track to write the next chapter of a political story that was briefly interrupted in 2008. Back then, she conceded the Democratic presidential race to Barack Obama in a speech that lamented "we weren't able to shatter that highest, hardest glass ceiling this time," but she added proudly, "it's got about 18 million cracks in it," a tally of her primary votes.

The roll call this year, when each state announces its delegate totals from the primary season, will affirm a nomination Clinton locked up weeks ago. Maryland Sen. Barbara Mikulski, the longest-serving woman in Congress, will submit Clinton's name to kick off the ritual. But talks were still underway Tuesday about how it will end.

It remained unclear whether Sanders would interrupt the process to ask that Clinton's nomination be approved by acclamation. That's what she did on Obama's behalf in 2008 to indicate their rivalry was truly over.

Sanders suggested Tuesday he wouldn't rush to make that gesture early, mindful that cutting off his restive voters could cause an outcry.

Once the nomination is sealed, the Clinton campaign planned to turn to a Day 2 program dubbed "Fights of Her Life," highlighting her advocacy for children, health care and Sept. 11 recovery efforts, the campaign said.

The speakers also will include the "mothers of the movement" -- the mothers of Eric Garner and Michael Brown, black men whose deaths at the hands of police helped spawn the Black Lives Matter protests.

The moment will not be without controversy: Philadelphia's police union complained that Clinton was showcasing killings by police without giving equal time to the families of fallen officers. Clinton's campaign responded that two members of law enforcement also are on the convention schedule.

Clinton also is tapping her entertainment connections. Millennials Lena Dunham and America Ferrara, as well as Debra Messing, Elizabeth Banks and Tony Goldwyn will take the stage. Alicia Keys is slated to perform.

Other speakers include former Attorney General Eric Holder and former Secretary of State Madeleine Albright.

Clinton will be watching from her home in New York, her campaign said.

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Woodward reported from Washington. Associated Press writers Ken Thomas and Matthew Daly in Philadelphia, Nicholas Riccardi in Denver and Meg Kinnard in South Carolina contributed to this report.