I did explain why. When a bill, as written, allows for blatant violation of the Fourth Amendment under the guise of corabating illegal immigration, it reeks of racism.
Like I said, being for or against (liking or disliking) is poor wording. You'll be hard pressed to find many people who like illegal immigration who are not illegals themselves or employers who knowingly employ illegals.
Nonetheless, the vocal group is the one bitching about how the wetbacks aren't paying any taxes and sucking the system dry.