BRIDGETON, Mo. Former Vice President Joe Biden was a crowd pleaser at a St. Louis County union hall during a rally for Sen. Claire McCaskill, D-Mo., Wednesday night, but even his most ardent supporters are divided on whether Democratic leaders his age represent the future of the party.

Many of the current top-tier 2020 Democratic presidential hopefuls would be in their 70s if elected to the White House in two years. Biden would be 77, Sen. Elizabeth Warren, D-Mass., 71, and Sen. Bernie Sanders, a Vermont independent who caucuses with Democrats and sought the party's presidential nomination in 2016, 79.

That didn't perturb Alicia Daly, one of the younger members in the crowd that gathered Wednesday in Bridgeton, Mo.

"I think he should run," Daly told the Washington Examiner of Biden. "He's more centralized and he's authentic, and that's what we need at this very moment when the rhetoric is getting more and more ugly on both sides. Both parties like him. And he doesn't have to serve both terms. He could just do one term, so we regain some of the ground we've lost."

Her friend, Marc Randolph, disagreed.

"He's not a bad guy, but I think we need fresh blood," he said. "Millennials are one of the biggest voting groups we have in our political system, and I don't know whether they would come out for him."

Lynn Jegle, attending her first political rally despite casting ballots for Democrats for years, said Biden's tendency toward faux pas could also derail a hypothetical campaign.

"But then look at what [President] Trump has gotten away with, so maybe it won't matter," she said. "If he's the candidate, I'd support him. I'm hoping the Democratic Party has a panel of people to consider and vet before the convention."

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Two of the best on the party's bench of talent were Warren and former Democratic Massachusetts Gov. Deval Patrick, according to Tom Bauer, another St. Louis County voter.

"Elizabeth Warren has the fire in her gut, stands up to Trump, and represents that side of the spectrum that has the momentum," Bauer said, adding Patrick had a "spotless record."

"Deval Patrick may be young, but Elizabeth Warren might as well be young," he continued. "I was a huge Bernie Sanders supporter, and his age didn't bother me at all. I think he was right on all the issues," he added.

Biden himself admits age is a "legitimate" concern for voters.

"If I were to run, I think they would judge me on my vitality," Biden told CBS News in October. "Can I still run up the steps of Air Force Two? Am I still in good shape? Do I have all my faculties? Am I energetic? I think it's totally legitimate that people ask those questions."

Biden joined McCaskill in the stronghold of Missouri Democrats Wednesday as she fights for her political future against Republican challenger Josh Hawley, the state's attorney general. A Fox News poll released earlier in the evening found the pair were tied with less than a week until Election Day.

McCaskill addressed concerns about the perceived lack of Democratic party-building during her brief remarks.

"People who don't think we have young stars coming up in the Democratic Party in Missouri, how about Cort and Wesley?" she said, referring to Missouri's 2nd Congressional District candidate Cort VanOstran and Wesley Bell, who is running to become St. Louis County prosecutor.