There is a cliché that in the past the Republicans were the liberal party and the Democrats were conservative, but this is somewhat misleading. For much of the early 20th Century both parties were very broad churches, with both parties having progressive and conservative wings, with the balance of power within each party often dependent on state and regional circumstances. It wasn't until the 60s and 70s that the two parties were fully consolidated along ideological lines. Is it possible to prevent the two parties from becoming ideologically consolidated on a national level, and if not how long can it be put off?