I grew up in a place with hardly any Jews that I know of. I confess to ignorance of why this is such a strongly hated group by certain factions, whether in the US or abroad. I mean, one doesn't see roaming gangs of kids with yarmulkas making trouble, as far as I know.
I suppose it's kind of a loaded question but with the recent resurge of incidents and references I got to thinking about it again.
Note that these are not my views but an answer to your question.
1) Jews regard us as dirty (unclean), they will not shake our hands, they keep themselves separate and think themselves better than us (the chosen people).
2) They give better deals to the Jews than the rest of us.
3) They don't contribute to the general good (specifically Jewish charities).
4) They wear stupid clothes
5) They have a stupid haircut
6) They speak their own language
7) They support a government that oppresses my people (only applicable if you are muslim?)
Most of these apply to the 'obvious' orthodox jew.
Of course many of these things can be applied to other groups e.g. Pakistanis. Often also subject to racism.
I think there is something in humans that make them resent the obvious other. Something that needs educating out of us. I think it is important to ensure that racism is not allowed.
Personally I would not walk round Bradford wearing a salwar kameez and cover my hair (hijab), but was 'forced' into it to by my mother for particular occasions. I do feel that those women wearing a Niqab are alienating; I feel that they feel superior to me so I do irrationally resent them. Having lived in North London, I can see how people can feel that wearing different clothes and speaking amongst yourselves a language other than English, having separate schools, makes you seem 'aloof'.
(To be fair to my mother I was a compliant and quiet teenager so being forced meant being told to do so.)