The mitigating circumstances are that President Obama has no global friends or allies. He has alienated everyone who deals with him (Merkel, Brown, Netanyahu, Sarkozy, Singh and Japan). He will still be able to do plenty of damage because he will still garner attention for 2-3 years after leaving office.
We've already had one U.S. president who was a traitor after leaving office. John Tyler became a member of the Confederate Congress.
My suggestion is that the 2012 Congress, which could be Republican, begin hearings on Jimmy-boy Carter for treason. Just hold a few Congressional committee hearings on the subject. Jimmy-boy went to foreign countries and spoke against President Bush and the Congressional mandates to invade Iraq. That has to be an appropriate stimulus for considering Jimmy-boy treasonous.
The purpose of the hearings would not be to try Jimmy-boy but to scare the current sitting President.
What do you think?