"I don't think he'd be our strongest nominee, no," Clinton told ABC News in an interview aired Tuesday.

"That's what this primary process is about," Clinton continued. "Let's see who emerges, but for everybody voting today or in any of the contests ahead of time, the most important issue is who can defeat Donald Trump."

Clinton's comments come on Super Tuesday, the biggest day of the 2020 contest. Voting is underway in 14 states and one US territory, and the critical contests will decide about one-third of all pledged delegates.

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