Why were Jewish people disliked so much?

(Picking this up from some of the threads)

Why were and are there a multitude of campaigns against the Jewish people?
Some claim race, religion or politics but war or the threat thereof, genocide seems to follow Israel and its Jewish inhabitants. Is it because they are simply too powerful and wealthy?
Did a Jewish generation or leader start this sometime back?
Will it ever see an end?

Please note this isn't a thread to vent hatred or personal issues.
It's a history lesson most likely.

Thank you.