CNN host Jake Tapper found himself stunned by new revelations about President Donald Trump's attempts to overturn the 2020 presidential election.

Tapper on Thursday talked with reporter Pamela Brown about her reporting on former Trump lawyer Rudy Giuliani working to create a slate of fake pro-Trump electors who would replace states' legitimate electors as a ploy to keep Trump in office.

"We are learning several Trump campaign officials led by Rudy Giuliani supervised efforts back in December of 2020 to put forward fake electors from seven states that Trump lost," Brown explained. "They were organizing ways to fill these elector slots, securing meeting rooms in state houses for fake electors to meet on December 14th of 2020. They sent around drafts of the fake certificates that ended up being sent to the national archives."

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She then talked about the role Trump himself played in the scheme.

"Trump and some of his top advisers publicly encouraged the alternate elector scheme in the seven states of Pennsylvania, Georgia, Michigan, Arizona, Wisconsin, Nevada, and New Mexico," she said. "However, behind the scenes now we're learning Giuliani and Trump campaign officials actively put that plan into motion."

Tapper appeared genuinely shocked by Brown's reporting.

"I guess lawyers will weigh in," he said while shaking his head. "But I cannot imagine how that's legal."

Watch the video below.

'Cannot imagine that's legal': CNN's Jake Tapper stunned by new revelations