If there is any lesson to be learned from the ghosts of Watergate, it is that the big-money support of a leader who has lost the ability to deliver the goods crumbles very quickly as the endgame unfolds.
The parallels between Hillary Clinton and Richard Nixon are not legal--they are political: specifically, how can a leader crippled by scandal and cover-ups govern?
In even blunter terms: how can a crippled politico deliver the goods to the special interests who bet their cash and political capital on the politico's ability to deliver favors?
Among the many ghosts of Watergate, one specter especially haunts Hillary: once the special interests and party stalwarts who defended you through every scandal and every cover-up--month after month and year after year, on the promise that you would deliver the goods upon ascending to the presidency--realize you are too damaged to deliver anything of value to anyone, why would they continue supporting you?
Once a politico has to declare "I am not a crook" based on legalese rather than a moral foundation, that politico's ability to lead has vanished. Hillary and her supporters rely entirely on legalese parsing of wrong-doing rather than on a self-explanatory, basic moral foundation of right and wrong.
Declaring "I am not a crook" because the wrongdoing escapes prosecution is the same as declaring "I am above the law." If the foundation of one's ability to lead is a reliance on legal parsing and allies in the Department of Justice squashing investigations while handing out immunity like candy on Halloween, the political capital required to lead no longer exists.