Can't we just switch to Proportional representation? It would eliminate this problem entirely.
That's the key, but it's unlikely, because it would require a constitutional amendment, and Republican and Democratic congresspeople are among the least likely to support it.
That's the major problem. Democrats and Republicans have entrenched the two-party system into election law in order to protect themselves and they are therefore the least likely to support any kind of reform, let alone an amendment to the Constitution.
IMO a much easier reform to pass than a proportional representation would be implementing instant run-off voting. That's how you'd get independents like Crist and other moderates elected. It would pull everything back to the center instead of pushing it out to the extremes like the current two-step system where the primaries eliminate the moderates and you end up with a choice between two extremists in the general. If people don't feel like they're wasting their votes on third parties then they'll be more likely to vote for them.
It's unclear (as far as I've seen) what party system IRV encourages.
