Why the US two party system is so entrenched

The other day, I came across this Big Think explanation by historian Sean Wilentz on why the US always seems to gravitate to a two party system. http://www.youtube.com/watch?v=Wnju7zOH_Zs Unfortunately, while I think Wilentz touches on the main points, his explanation doesn't seem as clear as it could be. To start off, he refers to the … Continue reading Why the US two party system is so entrenched