A former aide to Donald Trump’s presidential campaign delivered an extraordinary string of interviews with newspapers, websites and cable news outlets on Monday, defying special counsel Robert Mueller’s subpoena to testify before a grand jury, undercutting key claims made by the Trump administration on possible election collusion with Russia, and leading many of his interrogators to question his own mental state.

Sam Nunberg, who served as an adviser to then candidate Donald Trump in 2015, said Monday that he would refuse to appear before the federal grand jury investigating Russian interference in the 2016 election — and that he believes Mueller may have damning evidence against Trump.

“I think that he may have done something during the election,” Nunberg said in an afternoon interview with MSNBC’s Katy Tur, adding: “I don’t know that for sure.”

In a separate interview hours later with CNN, Nunberg continued to undercut the Trump administration’s claims that no collusion had taken place between its campaign staff and the Russian government to influence the outcome of the 2016 presidential election.

“I believe Carter Page colluded with the Russians,” Nunberg told host Jake Tapper about the former foreign policy adviser who has become a focal point in Mueller’s investigation.

Nunberg was also asked by Tapper whether he believed the president was telling the truth when he said he “knew nothing about the meeting” between Russians and members of his campaign team at Trump Tower in June 2016.

“No,” Nunberg replied. “He talked about it a week before. And I don’t know why he did this. All he had to say was, ‘Yeah, we met with the Russians.’”

Photo: Evan Vucci/AP

Throughout the day, Nunberg took credit for several of Trump’s signature campaign promises, including the construction of a wall along the southern U.S. border and a ban on immigration from Muslim-majority countries. He also reiterated his message to Mueller.

“I’m not cooperating,” he told Tapper. “Arrest me.”

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During her daily press briefing, White House press secretary Sarah Sanders dismissed Nunberg’s speculation about what sort of case Mueller may have built against the president.

“I definitely think he doesn’t know that for sure because he’s incorrect,” Sanders said. “As we’ve said many times before, there was no collusion with the Trump campaign.”

Earlier, Nunberg told the Washington Post that he received a subpoena from Mueller’s office to appear before the grand jury. Nunberg said the two-page subpoena is seeking documents related to Trump and nine other people, including all email exchanges he may have had with campaign officials during and after his time on the Trump team.

Former FBI Director Robert Mueller; former Trump campaign aide Sam Nunberg (Photos: Alex Wong/Getty Images; Business Week/Yahoo View)

Nunberg, who was interviewed by Mueller’s team last month, said he will refuse to appear before the grand jury and will not turn over any documents — in particular, his correspondence with former Trump campaign CEO Steve Bannon and ex-adviser Roger Stone.

“I’m not spending 80 hours going over my emails with Roger Stone and Steve Bannon and producing them,” Nunberg told the Post. “Donald Trump won this election on his own. He campaigned his ass off. And there is nobody who hates him more than me.”

If Nunberg does refuse to cooperate, he could face federal contempt of court charges — a possibility he dismissed in his interview with MSNBC.

“Let him arrest me,” Nunberg told the Post. “Mr. Mueller should understand I am not going in on Friday.”

Special counsel Robert Mueller. (Photo: Evan Vucci/AP)

“I think it would be really, really funny if they wanted to arrest me,” he told Tur. “I’m not going to cooperate when they want me to come into a grand jury for them to insinuate that Roger Stone was colluding with [WikiLeaks founder] Julian Assange. Roger is my mentor. Roger is like family.”

Echoing Trump, Nunberg called Mueller’s investigation a “witch hunt.”

“What does Bob Mueller need to see — my emails when I send Roger and Steve clips and we talk about how much we hate people?” Nunberg wondered.

After having spent hours answering questions on cable news networks, his responses lit up social media and made him the No. 1 trending topic on Twitter, Nunberg returned for a second CNN interview. Host Erin Burnett cut to the chase with a question.

“Talking to you, I have smelled alcohol on your breath.”

“Well, I have not had a drink,” Nunberg replied.

When Burnett pressed him, Nunberg repeated his claim that he had not had a drink. “Besides my meds. Antidepressants, is that OK?”

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