Mr. Rewrite was interested to hear about this correction based on an editorial cartoon. You can see the before/after above and the corrected cartoon here.
Here's the deal: The correct term is "Hear! Hear!" An idiom expressing acclamation, "Hear! Hear!" is short for "Hear ye!" or "Hear him/her!" Dictionary.com says it originally was an imperative shouted to call attention to a speaker's words.
Mr. Rewrite always cautions against placing too much trust in Wikipedia, but he likes its take on the meaning and origin of "Hear! Hear!"