2)It may not be comparable to slavery, but certainly to the civil rights struggle.
Violence against minorities to put them in their place, or just because? Check
Making minorities second class citizens? Check
Using religious doctrine to keep them there? Check
The sereotyping and making caricatures of minorities by the media? Check
Discrimination by establishments against serving said minorities? Check
Sure, there are many differences that keep it from being an exact equivalent (such as that gays can pass as straight while blacks can't pass as white, although we could argue that each minorities behavior was regulated into acceptable and unacceptable based on what made the oppressiong group comfortable and uncomfortable, and draw another parallel there...), but saying that they're not comprable is really ignorant.