The Google election data (link here) would be a fun dataset to play around in Tableau (link here), except I don't have the time right now.
Note that Google surveyed the population with the following questions:
1. Who do you want to win the US Presidential Election?
2. Regardless of who you want, who do you think will actually win the Election?
In regards to question two, Justin Wolfers (and co-author David Rothschild) noted in a paper (link here) that framing the question this way yields more accurate results.
I haven't look at the underlying data closely, but I would think the Google dataset should be able to either validate further (or cast doubt) on the paper finding. There’s also a NPR article about this (link here).