Not that I want to stick up for the Times, but the sampling error is a function of sample size. Since the number of blacks in the sample is smaller, the sampling error will be larger. Basically, the Sample error may be calculated as 1 divided by square root of sample size.
Disclaimer: It has been about 20 years since my last stats class.
frankjr,
Just so you know, there are a few folks that think the poll is bogus.
http://www.freerepublic.com/focus/news/1484981/posts