Former President Donald Trump's hush money trial, scheduled to begin later this month, is so critical because it was in many ways the precursor to his scheme to overturn the 2020 presidential election, legal expert Norm Eisen told CNN's Sara Sidner on Tuesday.

Manhattan District Attorney Alvin Bragg is prosecuting the case as felony business fraud that was undertaken in service of covering up an illegal campaign finance scheme to conceal Trump's affair with adult film star Stormy Daniels from the voting public ahead of 2016 — and prosecutors are reportedly planning to bring in tons of witnesses from inside Trump's circle to prove it.

It will start this month, and is the only of Trump's four cases that is essentially guaranteed to be heard before the November election.

"You're speaking ... about the witnesses, which is usually who are the most protected, and of course, the jury," said Sidner. "Trump's former press secretary, speaking of witnesses, Hope Hicks. David Pecker, the former executive, The Enquirer, who squashed the stories that were negative about Donald Trump. Michael Cohen, Trump's former attorney, who has turned on Donald Trump. The former Playboy model who also accused Trump of having an extramarital affair, Karen McDougal. And of course, Stormy Daniels herself, are all on the witness list. What does this list tell you? See Kellyanne Conway there as well?"

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"Sara, when I was counsel for the first impeachment of the former president, we investigated this identical set of facts including many of these witnesses," said Eisen. "I took Hope Hicks' deposition because the same, as the judge put it, alleged interference with an election gives rise to impeachable offenses as well, and I think that the prosecution, Alvin Bragg, has a case here. If they're calling Hope Hicks, they're calling these other witnesses."

And all these witnesses are crucial, Eisen said, "because they've meticulously put together a case that they're going to present to the jury of how Donald Trump allegedly — let's remember, he's innocent until proven guilty — but he allegedly kept vital information from voters in the 2016 election. That's the case of voter deception and alleged election interference. It's a gateway drug to him doing the same thing, allegedly in 2020."

In other words, Eisen added, the fact "they have critical information in the determination of D.A. Alvin Bragg shows you how wide the case spreads out."

Watch the video below or at the link here.

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