It's easy to attack him for it, but the truth of the matter is: the Zionist billionares that fund the Democratic party won't let him say anything else if he wants a chance at the white house.
And those zionist billionares have been using Israel for decades to suppress socialism in the middle east, while using campaign finance to do the same in the US.
He is helping those that he can by playing the game in a deeply flawed system.