President Donald Trump has accused former President Barack Obama of treason without any evidence.

Trump, known for constantly criticizing and accusing his predecessor Obama of crimes, though never naming them, has again repeated his claims. On Monday, in an interview with CBN News, Trump said Obama spied on his campaign and had committed treason in connection with Russia probe in 2016.

“It’s treason,” Trump said. “Look, when I came out a long time ago, I said they’ve been spying on my campaign. I said they’ve been taping, and that was in quotes, meaning a modern day version of taping, it’s all the same thing. But a modern day version. But they’ve been spying on my campaign.”

There is no evidence that Obama spied on Trump. The U.S. Constitution states, “Treason against the United States, shall consist only in levying War against them, or in adhering to their Enemies, giving them Aid and Comfort.”

Trump and his supporters have been constantly calling Russia probe a “witch hunt” and dismissed the FBI investigation as biased.

In recent months, Trump has also started the term “Obamagate” on Twitter, sparking conspiracy theories that Obama officials framed Trump and his officials in relation to Russian interference to sabotage his presidency.

Trump, in addition to accusing Obama of treason, also called for Obama administration officials in jail, saying they would have been “executed” had it happened “in different time.”

“If it was the opposite, two years ago, 25 people would have been convicted and they would be sent to jail for 50 years. And by the way, if it were 100 years ago, or 50 years ago, they would have been executed, but we’re in a different time,” he said.

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