These are generalized grievances ("somebody hurt my feelings!") looking for a specific but increasingly illusive cause!
Al Gore is upset about the environment but he isn't exactly sure why. It might be anthropological global warming or maybe it's the cooling or, perhaps, it's just the stormy weather in his neighborhood.
In the final analysis, he hitched his star to the environment...and the environment hasn't lived up to its side of the bargain.
Same for Obama and Al Sharpton, they hitched their stars to racism...and since it didn't live up to its side of the bargain, they are creating/fabricating stories/lies from whole cloth.
Someone must pay for Trayvon...let's string up GZ. The law doesn't apply here, because GZ is white.
Let's get a rope and a tree.