I think that the 'uncommitted' voters are mostly coming from that group of people, who want a government that doesn't fuck with them or their livelihoods, and/or family structure, and well-being. They don't see either candidate that they can talk themselves into, who can, either make it better...or, stop making it worse.
Why else wouldn't you decide and be 'Uncommitted'?

....and NO, they aren't believing either side's propaganda, either...not even the Tea party, the Progressive's, the Libertarian's or registered 'Independent's'.....frankly, I think there is a rather large group of the electorate, who, for good reason, just DO NOT believe or trust the shit that comes out of Washington, and presented to us 'for human consumption'.
I think I may fall into that category...and why not??...I've been right, more often than not....by a long shot....along with others, who are like-minded.

Respectfully,

GfS