The Roll-Reversal Between the Democrats and Republicans

Every once in a while, you run across a video clip that is well done to the point that it leaves you speechless. That happened to me recently. I've always been interested in the roll reversal among the political parties that has occurred over the past 150 years. From the Democrats and the Whigs to the Democrats and the Republicans, these parties have completely exchanged points of views over that period.  Today's Democrats are much more closely aligned with the Republican Party of the 1950's. Today's Republican Party is much more closely politically aligned with the Democratic Party of the late 1800's and very early 1900's. 
There are two video clips below that discuss how we got there. They're a little on the long side, but provide some really fascinating insight into how this transformation occurred and how the political styles of the parties have evolved over the last century.