The exit polls from Nevada provide more evidence that Obama has been unable to break out of his ceiling of approximately one-third of the white vote. In fact, in each of the three Democratic contests thus far, Obama's support among whites has been remarkably consistent:
New Hampshire: 36%
If this 35% ceiling does, in fact, exist, it's interesting to compare it to Jesse Jackson's performance in 1988. Despite the passage of 20 years and the fact that Jackson and Obama are very different candidates and personalities, Obama hasn't performed significantly better than Jackson. During the 1988 primaries, especially once the race narrowed down to Dukakis and Jackson, Jackson's white support ranged between 20 and 35 percent.