That is likely but Obama could actually still win without Ohio. He would have to take CO and IA in addition to holding WI, MI, and NV so it could still be awhile even if Ohio is called earlier.
I gotta admit I am surprised how many on both sides are feeling this is going to be fairly clear cut on Tuesday night.
The thing is, from a math standpoint, it would have to be REALLY close not to know by late Tuesday night. In Ohio, for example, Obama won in 2008 by under 5%... but that was still a sizable margin of 262,000 votes. States routinely get above 90% of votes tallied by 10 or 11 the night of voting. When you get a proportion that high, even if Obama/Romney wins a state by just 1%, the margin of votes is such that you effectively know the final result. It has to be ridiculously close - like, 0.2% or less - to not have a good idea by late Tuesday night. Now, whether the losing candidate will concede - that's another matter. No matter what, this is likely to be close enough to where lawsuits are filed and complaints are made, and the trailing candidate may wait a day or two to see if any gain traction. Not to mention the possibility of automatically-triggered recounts (sub-0.5%). But I think most reasonable people will understand who the victor will be by the time they go to bed tomorrow night.
^ Those are good points but this is a close election in most of the battleground states the majority of the polls have the candidates tied or well within the margin of error. It seems very likely it could come down to .2% of the vote in at least one of the decisive states. Another factor is that there are new voting laws and procedures in many states that might lead to more confusion. Let's not forget the army of lawyers ready to litigate.
Here is an article about all of the potential problems that could happen during the election. http://nbcpolitics.nbcnews.com/_new...r-nightmare-scenarios-for-what-could-go-wrong