Have you not watched any news on American politics? A two-party system is a cancer to freedom and democracy. All we would be doing is trading one problem, for another much larger problem. The major parties are terrified of the rise of minor parties in the last ~15 years. Neither has held a majority in the Senate since Howard, 2004-2007. That is a good thing.

What you’re suggesting is to throw the baby out with the bath water.