Good domain name. I would definitely wait until a year to six months before election time to sell it. Unfortunately, I think it would have been better to sell it prior to the 2008 election when the media was hyping Obama 24/7.
As to value, the only reference sale I could find is ElectObama.mobi for $80 in a July 2007 Sedo auction. Based on that I would say high $xx to low $xxx. The .us ccTLD is more valuable than .mobi in my opinion, but you also have to take into account the disappearance of Obama hype.
I don't see much value in the name and the window for selling it will close quickly after the mid term elections. Do not wait too long and you might get somebody to buy it.