Not to sound like I'm singling you out on this, but I'm kind of tired of the "Obama is a once-in-a-generation" candidate rhetoric. Obama is a great speaker, a great campaigner, a great organizer, a great candidate, and, more often than not, a great president. But he's not some unique black swan event (outside of, you know, being the first black president). Democrats have had talented, articulate, charismatic candidates who could win the presidency with the help of whites, blacks and Hispanics before, and they will continue to do so. We can talk about this broad trend of the white working class leaving Democrats, but the party was able to win back enough of these voters after Nixon's southern strategy to elect Carter, Clinton (twice), and Obama (twice).
I'm not saying I expect Democratic presidents to win a majority of the white vote anytime soon -- if anything, that likelihood will keep shrinking. But there are enough white working-class voters in there margins to flip back for next time, as Dems have done five times before since the civil rights and voting rights acts sent Dixiecrats to the GOP.