A former adviser for the Trump campaign defended the president’s derogatory tweets about the FBI, saying they’re an “insurance policy” to protect from bias within the bureau.

“The president’s tweets are an insurance policy for the American people to make sure that its leading law enforcement organization remains unbiased,” Michael Caputo told CNN on Tuesday.

Trump has called the investigation into Russian meddling in the 2016 election a “witch hunt” and railed against the FBI, FBI Deputy Director Andrew McCabe and former FBI Director James Comey, who the president fired in May.

The president has questioned whether the FBI has remained unbiased in both its investigations into Russian meddling — which is now overseen by special counsel Robert Mueller — and Hillary Clinton’s use of a private email server.

Republicans began to question the integrity of the investigations after it was revealed a longtime FBI investigator who worked on both probes exchanged derogatory text messages about Trump with an FBI lawyer.

Mueller removed the investigator, Peter Strzok, from the Russia probe.

In one of the messages Strzok sent to lawyer Lisa Page, he wrote, “I want to believe the path you threw out for consideration in Andy’s office —that there’s no way he gets elected—but I’m afraid we can’t take that risk. It’s like an insurance policy in the unlikely event you die before you’re 40…”

It's believed "Andy" is a reference to McCabe.

Republicans jumped on the message and mention of an “insurance policy.” Sen. Chuck Grassley, R-Iowa, chairman of the Senate Judiciary Committee, said the text appeared “to cross the line into taking some official action to create an ‘insurance policy’ against a Trump presidency.”

But according to the Wall Street Journal, the message was referencing the FBI’s investigation into potential collusion between the Trump campaign and Russia.

When asked about Trump’s tweets about McCabe and other FBI officials, Caputo said he didn’t believe the president was “going after them personally,” but rather “going after them professionally.”

“This is politics as usual,” he said. “I know that’s disappointing for some people, but the president is highlighting this bias to the American people for a good reason. If there’s going to be an investigation, it must be unbiased.”

Caputo also said he believes McCabe should be “challenged on his impartiality,” particularly because his wife, Jill, received campaign donations from a political action committee backed by Virginia Gov. Terry McAuliffe when she ran for the Senate in 2015.

McAuliffe is an ally of the Clintons.

“I think the president is doing that, and I appreciate those tweets. I consider them an insurance policy for America,” Caputo said.