host...two procedural reasons (as opposed to policy reasons) why I dont buy your scenario.
New Voter Registrations
New voter registrations are at an all time high, particularly in many of the battleground states in a manner that favors either Obama or Clinton over McCain. Here is a recent report, The Big Mobilization (pdf)
Beyond that, most other studies and polls (along with Obama's unprecedented online campaign fund raising drive involving millions of contributors) point to a strong majority of these new voters as being Obama supporters....young voters and black voters. And Obama is building on that with a grassroots, 50-state voter registration drive that was rolled out last week.
Voters Want Change
Nearly all polls of all demographic groups and across the political spectrum (with the exception of the far right) want change.....polls that the country is moving in the wrong direction are at an all time high, surpassing 80% (direction of country polls)....
....and right or wrong, far more voters (particularly those new voters and a majority of Independents) view Obama as the potential "agent of change" as opposed to either Clinton or McCain.
The Republican attack machine will be in full force with either candidate and Clinton has far more baggage and far higher negatives among most voters, particularly among Independents. Obama has also demonstrated an effective rapid response team (note the recent charge/response re: Bush's remarks about Democrats (particularly Obama) being terrorists "appeasers". Both Bush and McCain had to clarify that they were not referring to Obama.)
However, I still have concern about the hidden race factor. There is just no way to assess its impact.