It depends on what you mean by an extended period. Cases in point-- global warming, reverse discrimination, the war on poverty, the Clinton Dynasty, Jesse Jackson, the Madeline Albright view of foreign affairs . . . need I go on?
Not these ridiculous claims, not during the general election when focus is narrowed to two opposite candidates.
“Lazy” won’t work because he will be seen campaigning every day. “Too old” won’t work because many presidents in the past have been older.