Daily Swing State Tracking Poll (Swing State Daily Tracking: Romney 47%, Obama 46%)
Rasmussen Reports | Tuesday September 18, 2012 | Scott Rasmussen
In the 11 swing states, Mitt Romney earns 47% of the vote and the president is supported by 46%. Three percent (3%) are not sure, and four percent (4%) are undecided.
In 2008, Obama won these states by a combined margin of 53% to 46%, virtually identical to his national margin.
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A question here. What's the difference between "not sure" & "undecided"?