The first piece of evidence is the casual integration of races in the typical Obama crowd. Democratic rallies have contained similar racial mixtures in the past, but never on the scale that was present in 2008 and it has never been a winning recipe until now. It strikes me that the Obama coalition resembles the Rainbow Coalition that Jesse Jackson tried to assemble. You may recall that Jackson’s message also centered on hope. (Remember his Keep Hope Alive slogan?) Jackson was prescient, but he lacked the cross-cultural appeal of Obama. 
McCain’s crowds were almost uniformly white. These crowds also tended to be more motivated by what they were against than by what they hoped to build for the future. Which type of crowd do you think represents the way forward for the nation? Which one represents a more accurate reflection of America? Clearly, there has been a shift. While Bush won two elections by appealing primarily to his conservative, white base, the nation's demographics and social attitudes are now such that this strategy no longer works. Broader coalitions are necessary.
If Latinos remain 2-to-1 Democratic, it’s going to be a long stay in the wilderness for the Republicans. With Latinos becoming an ever higher percentage of the U.S. population, their political concerns simply must be accomodated by any candiate who wants to win a national election. Both parties saw the rise of the Latino vote coming during the preceding years and both made plays to win this group over. Ultimately, however, the prominence of white reactionaries within the Republican party drove the bulk of Latinos into the arms of the Democrats. This is significant since Latino voters are now numerous enough to deliver 3 or 4 western states that previously went for Republicans into the Democratic column.
Generation Y, as this age bracket is called, are more tolerant and socially relaxed than even Generation X-ers like myself, who in turn are more tolerant than their parents – and so on…. Racial, gender, and sexual preference differences are non-issues to these young people. Many of them were old enough to vote in the 2008 election and the emerging cultural influence of this generation (which can only grow) is further evidence of re-alignment.
Young people who are not old enough to vote participated in the process by registering people who can vote. Capturing the imagination of the young and harnessing their energy was one of the secrets to Obama's improbable success. The long-term impact of inspiring an entire generation should not be underestimated. Just as the economy has leading indicators that reveal future direction, the heavy involvement of young people in the Obama campaign predicts the future direction of our country.
The final piece of evidence for political re-alignment is Obama himself. The progessive forces in the country now have a charismatic and unifying leader in Obama whereas the conservative forces are sharply divided. The 2008 election was just the beginning of the re-alignment process.
