Clinton pulled out a narrow victory in Nevada of about 5%. Obama won everywhere outside of Clark county, and so he could have won the whole thing if the Strip precincts and union vote in Clark county had gone his way. However, the insider scoop is that AFSCME out organized the culinary workers on The Strip, and generally made the difference for Clinton across the county (UNITE-HERE apparently has little in the way of political staff). To put it one way, Obama might have had more unions, but Clinton's unions just did better. In some ways, that even reinforces one of Clinton's main campaign arguments: beyond grand speeches and huge rallies, she will work harder and get the job done both with and for what she calls "the invisible people."
Most of the last tens days in Nevada focused on unions, from the endorsements to the lawsuit over the Strip caucuses. This was definitely the Labor caucus, just as the DNC had designed it to be. In a very real way, the results are emblematic of the divide in the Democratic Party. The NEA tacitly supported Clinton, and AFSCME is now pretty much the flagship union of the AFL-CIO, at least in terms of political organizing. By contrast, SEIU and UNITE-HERE, both of which endorsed Obama in Nevada, are key unions in Change to Win. Old labor beat new labor, just as older Dems beat newer Dems.
On to South Carolina next Saturday. Clinton is now the clear frontunner, Obama needs a big win to stay in it, and Edwards appears to be done. Don't mess with AFSCME (warming: video not family friendly)
Update: Just to be clear, I don't trust the exit polls. They were way off on at least the results in Rural Nevada, as I discussed below. Further, expect them to rewieghted in a little bit. In other words, there is a lot of error, and re-weighting to be done.
And besides, even if Clinton did do worse among union households than non-union households, the point is that Obama was supposed to win union households by a decent amount. He didn't, and that contributed to his loss big time.
Another main factor, of course, was the Latino vote, where Clinton dominated. Nevada was chosen for this early date because of its high union and Latino populations. Clinton muted Obama's supposed advantage on Labor, and cleaned up among Latinos.