"In both cases, you have an American president accused, or suspected, of participating in the undermining of an election, facing off against one of the nation's top law enforcement officials, and when that official didn't back off -- firing them," Farrell said. "There are going to be lots of differences, but the elemental act is very similar.
Still, Farrell noted that we now have the advantage of understanding Nixon's motives. We don't yet know what was going through Trump's mind during his conversations with Comey.
It could be that this was a humanitarian gesture on the part of the President to help out his friend, Mike Flynn, and not a veiled suggestion that Comey back off," Farrell said. "Of course, now we've got a special counsel named to investigate all this, and try to find out whether it was Trump being Trump, or whether it was Trump being Nixon.
A handful of Democrats have already called for Trump's impeachment, but it is far too early to tell whether the President is really facing his own Watergate.
We don't know if there are any tapes -- a possibility that Trump raised in a curious May 12 tweet threatening Comey. Republicans are firmly in control of the House -- where any impeachment proceeding would originate -- and GOP lawmakers are standing with the President for now, though some have expressed alarm about his conduct.
CNN presidential historian Tim Naftali, the founding director of the Richard Nixon Presidential Library and Museum, noted that the investigation into Trump's motives and his actions is only just beginning.