Nearly two years into his investigation, special counsel Robert Mueller has not accused any member of the Trump campaign of conspiring with the 2016 election interference effort — and it's not clear whether he will.
But legal experts, along with the congressman leading the House Russia investigation, tell NBC News that the most important question investigators must answer is one that may never have been suitable for the criminal courts: Whether President Trump or anyone around him is under the influence of a foreign government.
"It's more important to know what Trump is NOW than to know what he did in 2016," said Martin Lederman, professor at the Georgetown University Law Center and former deputy assistant attorney general in the Department of Justice's Office of Legal Counsel during the Obama administration. "It's more important to know whether he has been compromised as president than whether his conduct during the campaign constituted a crime."
Rep. Adam Schiff, D-Calif., then ranking member of the House Permanent Select Committee on Intelligence, leaves a secure area where the panel meets at the Capitol, on Feb. 5, 2018J. Scott Applewhite / AP
Whether Mueller will answer that question in the absence of criminal charges is unclear. But in an interview with NBC News, House Intelligence Committee Chairman Adam Schiff said he is steering his investigation in a new direction to focus on it — and he will demand any relevant evidence compiled by the FBI or Mueller's team.
The California Democrat also expressed concern that Mueller hasn't fully investigated Trump's possible financial history with Russia.
"From what we can see either publicly or otherwise, it's very much an open question whether this is something the special counsel has looked at," Schiff told NBC News.
Schiff said the public testimony from former Trump lawyer Michael Cohen that in 2016 Trump stood to earn hundreds of millions of dollars from a secret Moscow real estate project is a staggering conflict of interest that must be fully explored.
"I certainly agree that the counterintelligence investigation may be more important than the criminal investigation because it goes to a present threat to our national security — whether the president and anybody around him are compromised by a foreign power," Schiff said. "That's not necessarily an issue that can be covered in indictments."
In fact, most FBI counterintelligence investigations don't result in criminal charges, experts say, because they tend to involve secret intelligence that either can't be used in court or doesn't add up to proof beyond a reasonable doubt. If the FBI assesses that a government official is compromised by a foreign adversary, officials often will quietly remove that person from a sensitive role or wall him or her off from classified information.
Obviously, none of that is an option for the president of the United States.
No official action was taken after Trump was accused of giving highly classified information to the Russian foreign minister in the Oval Office in 2017. As the president, he has the legal right to spill secrets to whomever he wants.
The White House has long insisted that the notion of a president in thrall to the Kremlin is ridiculous, pointing to the sanctions the Trump administration has levied on Russia in response to cyber attacks, election interference, and its actions in Ukraine.
Trump defenders complain that those who are now focusing on foreign influence have "moved the goalposts" — shifting emphasis to the issue of foreign compromise now that criminal charges involving "Russian collusion" seem less likely.
Trump has criticized Schiff’s approach, saying in a Feb. 7 tweet, "So now Congressman Adam Schiff announces, after having found zero Russian Collusion, that he is going to be looking at every aspect of my life, both financial and personal, even though there is no reason to be doing so. Never happened before! Unlimited Presidential Harassment."
But the question of Trump's motives regarding Russia has always been front and center for the FBI, as former Acting Director Andrew McCabe made clear in a recent round of media appearances. Neither Trump nor any of his supporters has been able to quell questions about the president's embrace of Russian President Vladimir Putin, including Trump's seeming unwillingness to criticize the Russian autocrat.Robert Mueller, then director of the FBI, testifies on Capitol Hill in 2011.Brendan Hoffman / Getty Images file
McCabe, who was fired for lack of candor in an unrelated matter, alleged that the president disputed intelligence that a North Korean missile could hit the United States, saying, "I don't care. I believe Putin."
That allegedly happened behind closed doors, but few will forget the public spectacle of Trump siding with Putin over his intelligence community on the question of U.S. election interference at last year's Helsinki summit, telling the world: "President Putin says it's not Russia. I don't see any reason why it would be."
McCabe said he could not rule out that the president was, in essence, a Russian asset. Trump has called McCabe a liar and "a disgrace to the FBI."
"What Americans should be concerned about is whether the president's Russia policy is not dictated by our national interest but is dictated by his desire to make hundreds of millions of dollars off a tower in Moscow," Schiff said.