Let's be clear about this. Voter intimidation doesn't work simply because the target audience doesn't know the law--or knows less about the law than the average American. While most US citizens don't know election law backwards and forwards--for myself, this was the first year I didn't try to foist my driver's license on the poll worker--most of us also have a reasonable expectation that if we register, we'll be able to vote. That's all we need to know.
Minority communities don't have that luxury. Unlike most of us, their wholly normal lack of election law knowledge is used against them, to make them unsure and make them fear running afoul of some law. Add to that the long and varied history of voter oppression and reprisals in this country, then add to that the lack of parity that minorities experience every day of their lives. It's easy to see why people might decide that a little thing like voting just isn't worth the risk.