I had an Obama supporer recently tell me that Obama is the only candidate who can "unite" America.  When asked specifically how Obama will "unite" us, they went off on the usual Obama rhetoric without giving any specifics, just that "Obama is great". 

No candidate in the '08 Presidential Election will unite the country.....none.  Obama can't even unite the democratic party behind him, much less the overwhelming majority of America.  The United States has two major idealogies going on, each with it varying degrees of extremism and mix of more independant minded voters.  The real problem is, Obama, nor any of the candidates, can really do anything to change that.

People on the left want a more socialist state, where government takes care of pretty much every aspect of your life.  Obama specifically wants government healthcare, restricted gun rights, more regulated business, etc.  Nothing he will ever do will convince a great part of America that those ideas are good for America.  On the same token, it can also be said that a great part of America would not be behind McCain because he supports winning in Iraq, and lower taxes.

With near impossiblity of a real third party candidate even getting near a majority, we have to work with what we got.  Unfortunately, there isn't much to work with, with the two party system we have here now.  With the exception of breaking the country off into two, I really don't see how this country will ever really be "united".