Mail Room to CEO in 20 Years, is It Still Possible?

Is it possible to go from bottom line worker to CEO in a Corporation in America? In fact history shows it is. We have had CEOs of McDonalds rise from lobby trash patrol. The CEO and CFO of Enterprise Rent-a-Car went from car washers to their positions. Often even with such examples critics will say that it is not possible today? I disagree, but they make their point of contention very strong and say;