Actually
None of us is really qualified to determine whether or not a politician is going to work out or not.
But we are all highly qualified to determine when a politician doesn't work out.
Maybe our leaders should be chosen by some other method, such as examination, appointment by a board, seniority gained in lower-level jobs or even by the casting of lots! THEN, after some time in office, the citizens can vote on whether or not they want to keep him.