US President Donald Trump lacks the level of intelligence that is required for “collusion” with Russia, says former US intelligence contractor Edward Snowden, noting that the ongoing Russian investigation by Special Counsel Robert Mueller won’t produce the results that Democrats hope for.

“I think people are asking for too much when they hope that the Mueller investigation is going to come up with kind of a smoking gun,” Snowden told The Intercept. “You know that’s not how the world works, life is not that simple.”

The former National Security Agency contractor said it was too “complicated” a process for a “wreckintg ball” like the Republican president to establish ties with Russia on such sensitive issues.

“And to be honest, everyone who has heard Trump speak for three minutes knows he’s a wrecking ball,” Snowden said. “This does not sound like the kind of person that you would want to engage in some kind of complicated Manchurian Candidate … the guy can’t even remember what he was going to say at the end of a sentence.”

US intelligence agencies claim Russia-linked hackers helped Trump win the 2016 US presidential action by provided WikiLeaks with damaging information about Democratic candidate Hillary Clinton.

Mueller is examining whether the Trump team was in contact with Moscow back then and whether the president has obstructed justice in the case.

Trump has labeled the investigation a “witch hunt” that is supposed to help Democrats gain on the Republicans in the mid-term congressional elections later this year.

Snowden said while Russian President Vladimir Putin would not have wanted to engage Trump, that doesn’t mean that Trump didn’t seek cooperation from the Kremlin either.

“That doesn’t mean that he didn’t want to cooperate, that doesn’t mean that he wouldn’t do anything to achieve an advantage,” he told The Intercept. “I just think we just need to be realistic about what an investigation can possibly find.”

Snowden began leaking classified intelligence documents in June 2013, revealing the extent of the NSA’s spying activities, including the massive collections of phone records of Americans and foreign nationals as well as political leaders around the world.

In 2013, Snowden fled to Russia and was granted temporary asylum there.

Trump has called Snowden a “traitor” suggesting that he should be returned to the US for prosecution.