Mike Pence is Spiro Agnew.
Agnew was Richard Nixon's Vice President and he too left office early, and in disgrace.
The only difference is Agnew - as far as we know - was not implicated in Watergate. Agnew's downfall came after the break in so he might, but his own illegal actions were punished.
We also don't know conclusively how deeply involved Nixon was because he was pardoned by Gerald Ford and there is the missing 18.5 minute tape.
Ford was the minority leader and Nixon wrote to him asking for recommendations for a new Vice President.
Ford ended up getting the job and then ascending to the Presidency. Some people speculate there was a deal that Ford gets the presidency and Nixon gets a pardon but that's rumour.
I expect Pence to go down WITH Trump so with Ryan resigning, the next one down in ascension retiring (Orrin Hatch), there will be a hell of a rabbit hole.