In any organization decisions have to be made. In the best, that decision-making authority is distributed so that people have the power to act at the appropriate level. Those people are accountable for their decisions, for the good or harm that comes from them.
There are times... there will be times, when only the senior leader can make the decision. Times when the harm or good are great and the conflicting interests or lack of data are great too. These are the times when senior leaders earn their keep, if they can make a good decision.
Any leader will have a track record of decisions. Some good some bad. When the good outweigh the bad, people will have confidence in the leader. And when the bad decisions outweigh the good, people will have little confidence.
Obama has two traits that concern me. One is a propensity to throw (or make a show of throwing?) under the bus allies who were previously convenient. The other is to make bad decisions about who he associates with, who he gives money to, how he holds folks accountable.
If he were elected, and the crisis comes up, would you want to be the one holding the briefing paper and saying "Mr. President, this is your decision."