For those of you who are too young to remember, Nixon resigned because Congress (both Democrats and Republicans) were going to impeach him for a) obstructing an investigation into a burglary of the Democratic National HQ, and b) using federal law enforcement to harass his (perceived) personal and political enemies (like Joe Namath).
If he's involved, its clearly an impeachable matter. So check out this paragrpah from the Posts report:
In remarks after the hearings, McKay said that officials in the White House counsel's office, including then-counsel Harriet E. Miers, asked him to explain why he had "mishandled" the governor's race during an interview for a federal judgeship in September 2006. McKay was informed after his dismissal that he also was not a finalist for the federal bench.
(emphasis supplied). If the "Bestest Whitehouse Counsel Ever" was involved, there is a good chance that the "Bestest President Ever" was too.