(CNN) Chicago Mayor Rahm Emanuel said Democrats shouldn't place their attention exclusively on President Donald Trump as they take control of the House of Representatives and look toward the 2020 presidential election.

"Don't focus immediately on Trump. ... You have something with the secretary of labor, you have with EPA, you have in the Interior Department, you have it at the Commerce Department, you have it at HUD. He has brought the swamp to Washington and flooded the plains, and I think Mueller will deal with Trump," Emanuel said in an interview with David Axelrod on CNN's "The Axe Files," airing Saturday at 7 p.m. ET on CNN.

"You have an entire government that is not on its game protecting the American people," he added. "The House should focus there."

Emanuel, who was chief of staff under President Barack Obama and an adviser to President Bill Clinton, told Axelrod that he thinks Trump is "making a big mistake" in special counsel Robert Mueller's Russia investigation.

"This President's decided to immerse himself in the investigation, the scandal, and not do a degree of separation ... and say, 'I'm not going to let that affect the business that the people elected me.' They're going to rue the day they didn't do that," Emanuel said.

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