Washington • Former Rep. Jason Chaffetz said he has “great respect” for Maryland Rep. Elijah Cummings, the Democratic chairman of the House Oversight and Government Reform Committee whom President Donald Trump has slammed over the weekend in tweets calling his district “rat-infested.”

Chaffetz, a Fox News contributor, worked alongside Cummings when the Utah Republican was chairman of the oversight committee and says he still has a good relationship with the Democrat. But he’s not going to defend Cummings against Trump’s attacks.

“I’m smart enough to not get in the middle of that spat,” Chaffetz said. “I have a good relationship with Elijah Cummings. I have great respect for Elijah Cummings. We disagree on most every policy, but that’s OK. You know I don’t like some of the things both of them said, but let them duke it out.”

Trump, apparently seething over Cummings’ investigations into the administration and criticism of his border policy, tweeted that Cummings’ Baltimore district is “far worse and more dangerous” than the U.S.-Mexico border and falsely claiming that the district is “considered the worst in the USA.”

“Cumming District is a disgusting, rat and rodent infested mess. If he spent more time in Baltimore, maybe he could help clean up this very dangerous & filthy place,” the president said in another tweet, misspelling the congressman’s last name.

On Monday, amid growing criticism of his incendiary tweets against several Congress members of color, Trump called Cummings a “racist.”

Cummings, for his part, said he works to make his district a better place.

“Mr. President, I go home to my district daily,” Cummings tweeted. “Each morning, I wake up, and I go and fight for my neighbors. It is my constitutional duty to conduct oversight of the Executive Branch. But, it is my moral duty to fight for my constituents.”

Chaffetz, who had visited Cummings’ district when the two were set to take the top leadership spots on the oversight committee, said he doesn’t see the president’s tweets as racist and that the sparring between Trump and Cummings was expected.

“Politics in Washington, D.C., is a full-contact sport,” Chaffetz said.

Meanwhile, Chaffetz is pushing his own agenda, attacking Democrats with a new book, “Power Grab: The Liberal Scheme to Undermine Trump, the GOP, and Our Republic.”

The book, the second Chaffetz has written since leaving Congress, will expose, the former congressman says, how Democrats will do anything to score power in Washington.

“I spent 8½ years in Congress," Chaffetz said, “and I relate firsthand stories of what happened and how it applies to what’s going on right now: How the Democrats will do and say most anything to try to grab power.”

He acknowledged that Republicans also push for more power, but “somebody can go ahead and write that book.”

“But, from my perspective, I think the sole purpose of what the Democrats are trying to do is grab back power," he said, “and I have hundreds of pages of examples.”

Chaffetz’s first book, “The Deep State: How an Army of Bureaucrats Protected Barack Obama and Is Working to Destroy the Trump Agenda,” hit The New York Times bestseller list and the forthcoming tome — expected in early September — has already garnered attention in conservative circles.

“Jason Chaffetz has consistently been in the fight and understands firsthand just how power hungry the Democrats have become,” conservative luminary Sean Hannity wrote in a blurb about the book. “Chaffetz lays out the case for how and why Nancy Pelosi, Chuck Schumer and their minions will do and say just about anything to tear down and smear hardworking, patriotic Americans that oppose their unrelenting desire to control our lives and press forward with their far-left agenda.”

Chaffetz wouldn’t say how much of an advance he received for the book, but “I did pretty well.”