I think Obama won the Nobel on November 4th 2008. When he prevented the guy who joked about bombing Iran from becoming president, when he kept the dangerously stupid Sarah Palin from becoming the VP, when he ensured that no more right wing zealots would be appointed to the SCOTUS, he won the Nobel peace prize. Without serving a single day in office, he accomplished the task of preventing the Republicans from doing what they've been doing for far too long.
So when the wingnuts whine about Obama not having done anything to deserve the Nobel, all we need to do is hold up this picture, point at it, and say
He saved us from THIS
Maybe the wingnuts won't understand why that was important, but who cares what they think? They will never be reasonable. What we should worry about are the centrists, who may well be swayed by the "Obama hadn't done anything yet" argument. Remind them what he saved us from, and that will answer their question.
If they have forgotten already, remind them what Obama saved us from:
An "experienced" man so stupid that he thought that Shiite Iran was supporting Sunni terrorists in Iraq.
A woman who's so scientifically ignorant that she thinks humans and dinosaurs coexisted.
A party that loves nothing more than to thumb their noses at the international community.
A party that supported Bush for eight years as he laid waste to peace and prosperity.
And on and on and on...
Obama saved us all from that, and for that he deserves the Nobel Peace Prize.
Of course they may have had other reasons, see poll below...