Is President Obama going to be President Carter take two?

I don't write much, indeed any, thoughtful stuff here - froth, films and funnies tend to be the preferred witterings here, but I do follow politics on both sides of the Atlantic and can't help wondering if Obama is going to be a one term President in the mould of Jimmy Carter.

There are many similarities;

• both came to power on the back of discredited Republican administrations
• both inherited difficult econmic conditions
• both brought optimism and promises to office, but struggled once in the White House
• both had to deal with difficult foreign policy issues in the Middle East - Israel/Palestine and Iran/Iraq
• both seem to be decent family men who have perhaps found gaining office considerably easier than actually being in office

I do wonder if the similarities may continue, for example;

• Carter was undone by the situation in Iran - could Obama? Indeed the odds seem more stacked against him as he has the additional issues of Iraq and Afghanistan to worry about.
• Carter faced a challenge from within the Democratic Party towards the end of his term, despite being the incumbent President - Edward Kennedy ran against him for the 1980 Presidential campaign. Could Obama, whose poll ratings are pretty low and dropping, face a challenge from, say, Hilary Clinton or another leading Democrat 'for the sake of the party'?
• There was initially no clear Republican challenger to run against Carter - in the end Reagan emerged and swept to power. Where will the next Republican challenger to Obama come from? Who are the up and coming Republican Governors?

In the end Carter's reputation grew upon leaving office - largely due to his work for Habitat for Humanity and his continued work around the Israeli-Palestinian conflict. I sense something similar may happen to Obama - he becomes a 'greater' world statesman after leaving office than he ever was as a one term President.