If that does turn out to be an apt analogy, it's hardly surprising that this is happening in many respects.
The crimes of Watergate came out of the Vietnam War, though this is poorly understood. The Watergate “plumbers“ were originally set up to plug the leaks about the Vietnam War.
And so, with the rise of the imperial presidency, it was hardly surprising that someone like Nixon would use the mechanisms of Empire -- the capacity for secrecy, for surveillance and for violence -- for his own political purposes. Indeed, Hoover, atop the FBI, had been doing so for decades.
The late Watergate historian Stanley Kutler writes in his book Abuse of Power that Nixon railed to his aides about papers regarding the Vietnam War that he thought were at the then liberal Brookings Institution.
“I want it implemented…. God damn it, get in and get those files. Blow the safe and get it.”
The documents Nixon apparently wanted to get hold of allegedly showed that Johnson curtailed the bombing of Vietnam in 1968 to boost the Democrats’ election prospects of winning the election that year.
A great irony now is that the establishment Democrats are going after Trump in a number of personal ways, but collude in others, and indeed stiffen up his use of violence. When Trump uses military violence in Yemen or Syria, he is lauded by presumed liberals like Van Jones and Fareed Zakaria as presidential.
The secrecy and the surveillance are sold to the public as necessary for their own protection, but the opposite is true. The little known Katharine Gun case highlights how the actual target of surveillance is frequently not "terrorism", but the threat of peace.
So, the Trump administration's ridiculous claims about the reasons for the Comey firing are fairly similar to the lying pretexts that U.S. officialdom used to justify the Iraq invasion. Empire is compatible with democracy only with a series of dehumanizing triple standards. It's fine there, just don't do it here.
In terms of Trump's own crimes, he is quite impeachable on the domestic emoluments clause, but the establishment Democrats seem quite uninterested in pursuing that.
They have focused on his apparent ties to Russia. There may well be something there, Trump is a corrupt figure and it's well within his capacities to engage in massive, if at times possibly buffoonish, coverup. But it is incredibly dangerous that the establishment Democrats seem intent on risking escalations with the other major nuclear power on the planet so they can beat Trump over the head.