The tweet is in response to something Hank William's Jr. said at a concert, which was:
We’ve got a Muslim for a President who hates cowboys, hates cowgirls, hates fishing, hates farming, loves gays, and we hate him.
Here is a screen capture of Baldwin's tweets responding to that statement. Remember, the most recent is first, so read in reverse order.
So Hank is racist because of his comment? He might be religiously intolerant, and you could try to argue homophobic, but it is not definitive from that statement. I don't see a mention of race in the statement though.
Baldwin's last tweet finishes things off by inferring that Obama is doing poorly in the polls because he is black.
So, who's the racist?