The lowest predicate for opening an FBI investigation is whether there is "information or an allegation" that a person has violated federal law. The higher standard is whether there are "specific articulable facts" that a person has violated federal law. Both have been met here. https://twitter.com/MSNBC/status/1346122119294414849

It's important to remember that investigating and prosecuting are two different things. There may be reasons that Biden's AG choose not to *prosecute* Trump for crimes he may have committed, taking into account various factors -- that is prosecutorial discretion 2/

But the FBI is duty-bound to investigate violations of federal law if they have any basis to believe that a crime has occurred. they don't get to pick and choose. This was articulated in the Mueller Report, in explaining why they investigated obstruction 3/

even though they knew that DOJ policy would prevent them from bringing charges against a sitting President: They needed to gather evidence while it was available, and memories still fresh. Then it was up to a future AG, or Congress, to decide 4/

Remember that if the FBI investigates, they will interview everyone. And unlike in Mueller's investigation, Trump's attorneys and pals won't have a get out of jail free card if they lie to the FBI...because Trump isn't going to be President after Jan. 20 5/

Although: One thing to keep an eye out for, in light of the above, is whether Trump's pardoning spree in the home stretch will include the lawyers and staff who were on this call with him.

P.S. Trump can't pardon future crimes, so none of these people can be pardoned for lying to the FBI before they do it. But he can pardon them for any (federal) crimes they might be liable for in participating on the call.