[Rolo]

I agree that the "situation" can create the "great" politcian, and again that "great" is subjective.

However my subjective feeling is that the current situation in the world could create a great president, if he/she had vision. Democracy vs. Fundamentalism, oil/energy peak, world population growth etc. All major problems, which have not reached their full scale yet, but many could do within 20-45 years. A visonary politician might not be able to single handed solve these problems, but he/she could begin the process, so we are not overwhelm with problems in the future.
I´m certain that when the above problems gets big enough, then some politicians will rise to solve them, but it will not be vision who drives them, but the hard reality of the world they will live in at that time.