I wouldn't quite say that we really need to switch to proportional or something else just yet. These type of fundamental changes have the potential for huge uni

I wouldn't quite say that we really need to switch to proportional or something else just yet. These type of fundamental changes have the potential for huge unintended consequences, and need to be looked at carefully from every angle. One of the properties of our system the way that it is is that all "radical" elements, where radical is anything outside the national status quo, must join one of the big parties and appeal at least somewhat to all of the interests in that party to get anything done. Going to this sort of proportional system breaks that, for all such radical interests. Sure, being able to vote for a useful Libertarian party, or a tech and science party, sounds nice. But there would also be the radical Christian party, the drug warrior party, the foreign policy hawk party, the isolationist party, union party, big business party, etc, and none of them will be moderated by the need to appeal to the rest of a large party. I also think that everyone is justifiably worried about what a major rewrite of the US constitution, which is what doing that would require, would look like right now.