Romney scores first negative bounce in poll's history

From the goldmine that is No More Mister Nice Blog:

 The question in the CNN/ORC poll (PDF) was "Does what you saw or read of the Republican National Convention in Tampa make you more likely or less likely to vote for Mitt Romney?"

More people said "less likely" than "more likely."

That's the first time a candidate has ever been underwater on that question in the history of CNN polling.