Trump calls Mueller investigation 'attempted coup,' Barr says 'spying' needs to be investigated Barr has said he wants DOJ to review how the counterintelligence probe began.

President Donald Trump on Wednesday blasted special counsel Robert Mueller's Russia investigation as an “attempted coup” that failed and praised Attorney General William Barr for saying he is investigating how the probe began -- a move congressional Republicans have long advocated.

“This was an attempted coup. This was an attempted takedown of a president and we beat them. We beat them," Trump told reporters at the White House ahead of his departure for Texas. "So the Mueller report, when they talk about obstruction, we fight back. You know why we fight back? Because I knew how illegal this whole thing was: It was a scam."

At about the same time, Barr, on Capitol Hill, said “I think spying did occur: on the Trump campaign and he wanted to look into how it began and whether it was legally justified.

Trump also blasted what he called the "haters of Trump" and "dirty cops" and bad people" who worked on the investigation but, according to him, still found no evidence of the campaign colluding with Russia to influence the presidential election.

"What has been found during this period of time are the illegal acts of getting this whole phony investigation started. And hopefully that's where people are going now. That's where people are going, and it's very interesting. It was an illegal investigation," Trump said.

Trump said he still has not read the Mueller report and said he’s not interested in the report, beyond the possibility that the Justice Department could look into the origins of the investigation.

“As far as I'm concerned, I don't care about the Mueller report. I've been totally exonerated. No collusion, no obstruction,” Trump said. “I am not worrying about something that never, ever should have taken place."

As Democrats grilled Barr at a Senate hearing over his handling of the Mueller report, the attorney general surprised senators by saying he wanted to "explore what he called "spying" on the Trump campaign. "I think spying on a political campaign is a big deal."

“I think spying did occur. Yes, I think spying did occur," Barr said. "But the question is if it was predicated, adequately predicated, and I’m not suggesting that it wasn’t adequately predicated.”

Barr did say "There's a basis for my concern" without revealing more.

“I need to explore that," Barr continued. "Congress is usually very concerned about intelligence agencies and the enforcement agencies staying in their proper lane, and I wanted to make sure that didn't happen.”

After one senator raised concerns about his use of the term "spying," Barr switched to saying "surveillance."

Barr said he has not set up a team yet, but has "in mind having some colleagues help me pull all this information together."

Barr has assembled a team inside the Department of Justice to look into the start of the entire Trump-Russia probe and review whether the threshold for initiating a counterintelligence probe should be adjusted, according to a DOJ official.

That news was applauded by congressional Republicans who have long-challenged the genesis of the Russia investigation.

“I say God bless him,” Rep. Jim Jordan, the top Republican on the House Oversight Committee, said. “I think that's exactly what needs to happen, the American people I think want that to happen. We've certainly called on that for, I don't know, almost two years, I guess?"

"I've been very impressed with the way the attorney general's handled himself and I think the fact that he's going to go back and figure out what took place when this whole crazy thing got going," Jordan, R-Ohio, continued. "I think that that’s exactly what he should be doing.”

Barr testified publicly at a congressional hearing Tuesday that DOJ was "reviewing" this matter.

Rep. Mark Meadows, the chairman of the House Freedom Caucus, claimed he has reviewed the same documents he believes have piqued Barr's interest.

"I think his statement is consistent with documents that Jim Jordan and I have seen in private, and so his statement doesn't come as a surprise to either one of us. In fact it's consistent with what we have long believed and and have long trusted in in terms of the documents we've seen," Meadows, R-N.C., said. "The Attorney General knows those facts, and he said he's gonna start from the beginning and I trust that he'll do the kind of investigation that we want the United States Attorney General to do."

During Barr's confirmation hearing three months ago, he pledged to look into whether a counterintelligence investigation was improperly opened up by the Obama administration against Trump. For more than a year, the DOJ inspector general has been investigating allegations that early actions in the probe were improper.

"What I'm most interested in is getting started," Trump said Wednesday.

"Hopefully, the attorney general -- he mentioned it yesterday -- he's doing a great job -- getting started on going back to the origins of exactly where this all started, because this was an illegal witch hunt and everybody knew it, and they knew it too. And they got caught. And what they did was treason. What they did was terrible. What they did was against our Constitution and everything we stand for."

The matter dates back to Carter Page, a former foreign policy adviser for the Trump campaign. The FBI began monitoring Page in the weeks leading up to the 2016 presidential election because they alleged he had been recruited by the Russian government, which Page denied.

“The FBI believes the Russian government’s efforts are being coordinated with Page and perhaps other individuals associated with [Trump’s] campaign,” an application with the Foreign Intelligence Surveillance Court said. Since then, the president’s advocates on Capitol Hill and elsewhere have used the FBI’s surveillance of Page as evidence of a deep-state effort to subvert the Trump campaign.

ABC News' Mike Levine, Luc Burggeman and Trish Turner contributed to this report