He would be steady and calm, given neither to irrational exuberance or outbursts of anger. He would make mistakes, that's for sure, but he could be expected to recognize them, adjust, and move forward.
He would adjust his views to reality rather than trying to adjust reality to his views.
Obama's unprecedented appeal to younger voters is significant not only because it expands the electorate, which is vital. It's also a validation of his promise as a president to be free of the baby-boomer/Vietnam/segregation-era hangups.