Do undecided voters still matter?

How much benefit President Obama will garner from his improved performance at Tuesday night’s second presidential debate could depend heavily on the answer to a second question: Who was it that moved to Mitt Romney’s side over the last two weeks?

The often-heard answer to that question is that Romney’s strong performance at the first debate in Denver on Oct. 3 won over undecided swing voters. …

An opposing theory holds that Romney’s gains mostly did not come from winning over voters in the middle, but from energizing Republican and Republican-leaning voters who had grown discouraged about his campaign. [cont.]

David Lauter, Los Angeles Times