Many white liberals do support Booker for President. Others support someone else more. I cannot imagine almost any white liberals voting against Booker if he gets the nomination.
The Alt Right claimed that the only reason people voted for Obama was he was black. There are millions of other blacks, so there really must be more to selecting Obama than he was black. Now they say if we do not elect Booker, we are racists. We are not required to vote for Booker just because he is black.
Booker would probably make an excellent President. He would definitely be far better than trump. But Booker is still young, and does not have as much experience as I would like to see.