In practice, first-past-the-post voting is dysfunctional bordering on evil, especially when combined with gerrymandering wherein politicians select their voters rather than vice-versa. The entire result set of this mess - two parties and their primaries - is deeply screwed up. The practical challenge (imo) is to explain alternatives concisely to voters who might want to modify how their voting system works. But there are now experiments going on here and there.