Hillary Clinton, in DNC speech, says Kamala Harris can break 'hardest glass ceiling'

Former Secretary of State Hillary Clinton electrified the crowd on the opening night of the Democratic National Convention as she portrayed Vice President Kamala Harris as someone who could break barriers and reach a pinnacle that eluded her throughout her own political career.

"Together, we've put a lot of cracks in the highest, hardest glass ceiling," Clinton said in her rousing remarks after receiving a warm welcome from the crowd at the United Center in Chicago. "And tonight so close to breaking through once and for all."

Harris will be the second woman in history to accept a major party's nomination for president following Clinton, whose monumental 2016 run made history but ended with a general election loss to Donald Trump.

Clinton began her remarks by thanking President Joe Biden for his leadership and for returning decency to the White House. But she quickly switched gears to lay out the historic progress that's led to this moment, recalling Shirley Chisholm's presidential run and Geraldine Ferraro being the first woman to be nominated as vice president.

"And then, there was 2016 when it was the honor of my life to accept our party's nomination for president," Clinton said of her own experience. "And nearly 66 million Americans voted for a future where there are no ceilings on our dreams. And afterwards, we refused to give up on America. Millions marched. Many ran for office. We kept our eyes on the future."

"Well, my friends, the future is here," she said to cheers.

Clinton said she wished her mother and Harris' mother could see them, and believed they would tell them to "keep going." The audience then echoed back shouts of, "Keep going!"

Comparisons of Clinton and Harris' campaigns have begun to emerge as Harris ramped up her operation in the weeks after Biden's decision to step aside.

Several Democrats told ABC News they are feeling buoyed by Harris' candidacy and how she's reenergized the party, but are worried about being overconfident against Trump after what transpired with Clinton eight years ago.

Clinton, who first ran for president in 2008 but lost in the primary race to Barack Obama, was successful in 2016 in clinching the nomination after defeating independent Sen. Bernie Sanders.

A bitter, ugly general election contest ensued between Trump and Clinton. Trump took to calling Clinton "Crooked Hillary" and the "devil." Clinton called half of Trump's supporters a "basket of deplorables," which critics called a mistake that alienated some voters.

A Trump fundraising email sent out Monday hours ahead of Clinton's DNC remarks highlighted her past "deplorables" comment and claimed she was "about to unleash hell on MAGA."

In her speech, Clinton took a shot at Trump for being convicted on 34 felony counts (a verdict he's vowed to appeal) saying he "made his own kind of history" and "fell asleep at his own trial."

After those comments, the crowd broke into chants of "Lock him up!" to which Clinton smiled and nodded her head. Trump called for Clinton to be imprisoned multiple times in the 2016 campaign, with "Lock her up!" calls frequently emerging at his rallies.

Polls in 2016 had shown Clinton ahead leading up to Election Day, but when results came in they showed Trump leading a stunning upset by grabbing several key battleground states. Clinton conceded the next morning.

Clinton referenced polls in her speech, noting that while Harris has been polling better against Trump than Biden, Democrats can't take their foot of the gas.

"No matter what the polls say, we can't let up," she said. "We can't get driven down crazy conspiracy rabbit holes. We have to fight for the truth. We have to fight for Kamala as she will fight for us. Because you know what? It still takes a village to raise a family, heal a country and win a campaign."

Clinton recounted her loss in greater detail and what went wrong with her campaign in her 2017 memoir "What Happened." She wrote that she bore responsibility ultimately for the loss to Trump but described it being difficult to overcome stereotypes. She also directed some blame at former FBI director James Comey for reopening the investigation into her private email server 11 days before the election.

After the 2016 election, Clinton maintained a relatively low profile until 2020 when she campaigned for Biden after his success in the Democratic primaries.

Clinton spoke at the 2020 Democratic National Convention, saying she wish Trump had been a "better president" and praised Biden's character and his choice of Harris to be his running mate. She said they were a team who could "pull our nation back from the brink and build back better."

More recently, she penned a New York Times op-ed offering Biden advice on how to debate Trump before the June CNN showdown. Clinton called Trump a bully who "stalked" her on the debate stage in 2016 and urged Biden to be "direct and forceful."

After Biden dropped out of the race, in large part because his poor debate performance ignited Democratic fears about his age, Clinton wrote another Times op-ed offering a full-throated endorsement of Harris.

Clinton said that Harris can defeat Trump but warned she will face similar prejudices -- a theme she continued in her DNC speech.

"On her first day in court, Kamala said five words that still guide her. Kamala Harris for the people," Clinton said, referencing Harris' record as a prosecutor.

"That is something that Donald Trump will never understand," Clinton went on. "So, it is no surprise, is it, that he is lying about Kamala's record. He's mocking her name and her laugh. Sounds familiar. But we have him on the run now."

Describing Harris as someone who would "always have our backs," Clinton praised the vice president for her work on reproductive rights, support for military service members and commitment to the rule of law.

At times, some in the crowd appeared emotional as she spoke.

"I want my grandchildren and their grandchildren to know I was here at this moment, that we were here, and that we were with Kamala Harris every step of the way," Clinton said. "This is our time, America. This is when we stand up. This is when we break through. The future is here. It's in our grasp. Let's go win it."