Is it "Hear! Hear!", or is it "Here! Here!"?
My inclination is to think it's Here! Here!, but I could see it going the other way too.
Hear! Hear!... as in "Listen to what is being said. And by me requesting that all around hear what is being said, I am endorsing it!"
Here! Here!... as in "I agree with, and endorse what was just said. I do. Me. Right here. Here." or "I endorse you, sir. Me, standing here!"
I suppose too, it could be "Hear here!"...as in "Everyone here, in the vicinity of the speaker, hear what he has to say!"