(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.”

“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.

Looking ahead to 2020, Emanuel predicted that the 2018 midterm election marked a potential turning point for Democrats, particularly when it comes to making gains in suburban areas.

“I think if the Republican Party stays as angry as Donald Trump, as ugly as Donald Trump, I think that’s a unique opportunity for the Democrats to actually open up and build a stronger, more stable coalition that not only wins gubernatorial races and House races, but the ultimate prize, the White House,” Emanuel said.

He said Americans are ready for a foil to the President and that the country is “ashamed” and “exhausted” by Trump.

“Eight years of this would be something I’m not sure how long it would take for America to recoup — or recover from,” he said.

Emanuel said the best challenger to Trump would be young and a relative newcomer to politics — not someone like former Vice President Joe Biden, who this week said he is the “most qualified person in the country to be president.”

“I am trying to look for history to draw lessons. Jimmy Carter, Bill Clinton, Barack Obama — all younger than age 50, all from outside of Washington. … My general rule is that has worked for us,” he said. “The last thing I think we need is a nominee who owns Washington.”

Emanuel stirred controversy last month when he called Texas Rep. Beto O’Rourke, who was defeated by Sen. Ted Cruz in his bid for Senate, a “loser.”

“My point was about the party,” Emanuel said. “What party takes a person who led the party to the greatest wins in the House since the Watergate and says, ‘We are going to cut your knees off,’ and then says, ‘We want to nominate somebody who didn’t win’? It wasn’t about him. I admire what he did. It’s about our party that I don’t admire.”

Emanuel also discussed gun violence in Chicago, which Trump has repeatedly criticized.

Emanuel said that the city needs to deal with the combination of “too many guns, too little values.”

He also said Trump might be targeting him more than other big city mayors, and that the President uses Chicago as a “shorthand” for what he views as failed Democratic policies in cities roiled by gun violence.

“I have said and I have declared that Chicago will be a Trump-free zone. And I stand by that because I think the policies that he has advocated are quite divisive,” Emanuel said.

“There has been in the last 100 years, seven attempts to make changes to the police department,” Emanuel said. “I am convinced that the road we are on now is the one that will actually put this to bed and make the fundamental changes.”

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