It depends on your definition of hero, I guess. The fact that Gandhi and MLK did not use force to advocate for their opinions was mature and moral. They did not give up the first time. But maybe if the cause is correct, one might have to break the stated law, and become a hero.
The Watergate scandal was certainly encroaching on him
Nixon's was heavily being accused of defending the perpetrators of Watergate scandals through his failure to release white house tapes, that could have implicated his aides, and certainly himself in the Watergate scandal. His firing of prosecutor had juiced a co-impeachment frenzy across the country, and thus had to respond to these allegations.
Recycle and natural resources