Political polarization explained via Gallup: the Democratic Party in America has become more liberal over time

[youtube=http://www.youtube.com/watch?v=vs41JrnGaxc&w=600&h=315]

One of the biggest things we've been hearing about in American politics for the past 18-24 months is the increasing polarization and partisan breakdown of how things function. It all seems pretty logical, but now, via a new Gallup study of 18,000 Americans across 13 different 2013 polls, we…