Black Anti-Semitism

I've always had a suspicion that anti-semitism is either widespread or at least tolerated within black communities, but until now I never looked up hard numbers. The Anti-Defamation League has been keeping track of this since 1964, and as of 1998 they found that black Americans are leaps and bounds far more anti-semitic than any other race:

Confirming the three previous studies, black Americans remain considerably more likely than white Americans to hold anti-Semitic views. In the 1998 survey, blacks (34%) are nearly four times as likely as whites (9%) to fall into the most anti-Semitic category.

[...]

Among those blacks without any college education, 43% fall into the most anti-Semitic group. This number drops to 27% among African-Americans with some college experience, and stands at 18% among blacks with a four-year college degree.

So those numbers are from 1998. I did a cursory look to find more recent statistics but it seems that they stopped drawing attention to the racial discrepancy. They're happy to highlight differences based on gender, religion, and age, but not race. I don't have enough information to conclude that this is deliberate, but at first glance it does seem to be absent a compelling explanation.

I'd be really curious to know why anti-Jewish sentiment is so widespread. It can't all be the Black Hebrew Israelites or Farrakhan's influences.