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Robert Mueller says he's worried that future campaigns won't report foreign influence to authorities.

Rep. Peter Welch, a member of the House Intelligence Committee, raised the issue during his time.

"My concern is, have we established a new normal from this past campaign that is going to apply to future campaigns so that any one of us from the US House, any candidate for the Senate, any candidate for the presidency of the United States, aware that if a hostile foreign powers is trying to influence an election has no duty to report that to the FBI or other authorities?" Welch asked.

Mueller responded: "I hope this is not the new normal. But I fear it is."

Welch went on to ask Mueller if he had any advice for Congress on protecting the electoral system.

"I would say the basis — the first line of defense really is the ability of the various agencies who have some piece of this to not only share explanation, but shared expertise, to share targets, to use the full resources that we have, to address this problem," Mueller said.