They should bring in preferential voting, so people can still vote for an independent without 'throwing their vote away'.
(How preferential voting works for those who don't know)
Say their are four candidates: Republicans, Democrats, Greens and Liberatarians. You vote for them in the order you want, for example:
1) Greens
2) Republicans
3) Democrats
4) Liberatarians
They then count up all the first preference votes, and the outcome might be: 10% Greens, 15% Liberatarians, 35% Republicans and 40% Democrat. Greens lost, so everyone who had greens as their first preference has their second preference counted.