"'I submitted my resignation to President Bush twice during that period and told him that - that I felt that he ought to make the decision as to whether or not I stayed on,' Mr. Rumsfeld said."
(New York Times)

I've never heard of this, offering to be voluntarily fired? Telling the president he has the right to fire him?? Resign or don't. This sounds as if he demanded that the President exonerate and support him, so he could have the cover of higher authority.