Nicholas Kristof reviews the questions about the Trump campaign that can be answered only by an independent special prosecutor who conducts a nonpartisan investigation, if that is possible.

Was there collusion between the Trump team and the Putin regime?

“There are a lot of dots here, and the challenge is how to connect them. Be careful: Democrats should avoid descending into the kind of conspiratorial mind-set that led some Republicans to assume Hillary Clinton was a criminal about to be indicted or to conjure sex slaves belonging to her in a Washington pizza restaurant. Coincidences happen, and I think there has been too much focus on Attorney General Jeff Sessions, not enough on Paul Manafort, the former Trump campaign manager. Here are 10 crucial dots:

“1. President Trump and his aides have repeatedly and falsely denied ties to Russia. USA Today counted at least 20 denials. In fact, we now know that there were contacts by at least a half-dozen people in the Trump circle with senior Russian officials.

“2. There’s no obvious reason for all these contacts. When Vice President Mike Pence was asked on Jan. 15 if there had been contacts between the Trump campaign and Kremlin officials, he answered: “Of course not. Why would there be?” We don’t know either, Mr. Vice President.

“3. There were unexplained communications between a Trump Organization computer server and Russia’s Alfa Bank, which has ties to President Vladimir Putin. These included 2,700 “look-up” messages to initiate communications, and some investigators found all this deeply suspicious. Others thought there might be an innocent explanation, such as spam. We still don’t know….

“7. A Trump associate, Roger Stone, appeared to have had advance knowledge of Russia’s disclosures through WikiLeaks of Hillary Clinton campaign emails. As early as August, two months before her campaign chairman John Podesta’s emails were released, Stone tweeted: “Trust me, it will soon [be] Podesta’s time in the barrel.” In October, six days before a dump of Clinton campaign emails, Stone tweeted: “HillaryClinton is done. #Wikileaks.”

There is no way to answer these questions unless there is an investigation. The investigation must be independent.

Nothing to hide, nothing to fear.