You’d think, wouldn’t you, that running the department of State or Defense (competently) would be a clear sign of some executive ability. But I don’t think a Cabinet official since William Jennings Bryan’s day has been offered as a real candidate for the Presidency. Why is that?
These days, the only viable positions one can hold are the Vice-Presidency, the Governorship of some state, or a position in Congress. I understand that there’s some small virtue in being tested by the electoral process, but certainly a Cabinet position also subjects you to tests and public exposure. Why do you suppose that it’s not more common for Cabinet members to run for the Presidency?