WASHINGTON – New Jersey Gov. Chris Christie said Sunday that Donald Trump Jr’s meeting with a Russian lawyer was a “bad idea” but he trusts Special Counsel Robert Mueller to give Team Trump a fair shake.

“Bob Mueller is a good man, in my experience with dealing with him when he was director of the FBI and I was U.S. attorney,” Christie told CNN’s “State of the Union.” “And I trust that he will be very careful to try not to go on a fishing expedition. There’s always a temptation to do that. I hope that that’s not what he does.”

One interaction Mueller and congressional investigators are probing is Trump Jr’s meeting with a Russian lawyer during the presidential campaign that was billed as a chance to get dirt on Hillary Clinton from the Kremlin.

“I think that everybody, in retrospect, knows this was a bad idea,” Christie said of the Trump Tower meeting.

Emails revealed that Trump Jr. was excited about the June 2016 meeting and welcomed a chance to get damaging information on his father’s opponent. But Junior said the actual meeting was a waste of time because the Russian lawyer never produced any opposition research.

President Trump helped craft a misleading statement about the nature of his son’s meeting, the Washington Post reported.

“Let’s not jump ahead of ourselves,” Christie cautioned about the president’s involvement. “We don’t know that the president knew about those e-mails or about the content of those e-mails. And so we don’t know what his own son told him about that meeting.”

President Trump and his allies have blasted Mueller’s Russian probe as a witch hunt and have sought to discredit his expanding probe.

Mueller reportedly convened a grand jury for his investigation.

Christie said the grand jury is a “normal step” and needed to issue subpoenas.

“That’s a typical thing to be done in any investigation,” Christie said.

But Rep. Adam Schiff (D-Calif.), the top Democrat on the House Intel Committee, said Mueller’s grand jury is a “significant development.”

“That wouldn’t be taking place if there was really no evidence, no evidentiary basis to move forward,” Schiff told CNN’s “State of the Union.”

To protect Mueller’s investigation, a pair of bipartisan lawmakers — Sens. Thom Tillis and Chris Coons — introduced legislation to allow special counsels to seek legal recourse if they are dismissed.

The bill is retroactive to May 17, when Mueller was named special counsel to investigate Russian meddling in the 2016 presidential election and potential Team Trump collusion.

Asked if the bill was directed at President Trump, Tillis (R-NC.) didn’t hide his concern. “There’s no question that it is because clearly, the date that we’ve made the bill retroactive to,” he told “Fox News Sunday.”

Tillis said Mueller should be allowed to complete his investigation and have a “definitive answer” on Russia’s influence. “I don’t believe the investigation is a witch hunt,” Tillis said.