If I wanted, say, single payer insurance, I wouldn't be able to vote for it because my democratic candidate wants to stick to halfassed and broken Obamacare, and the Republican wants to abolish it entirely. I have no meaningful way to exercise that vote, even if this is a majority opinion, and not particularly extreme since it's the status quo in most of the world. Ditto for anything affecting monied interests, since the two presidential candidates are by necessity deep in the pockets of wealthy interest groups right from the beginning of their expensive campaigns.
The only way out I see is through constitution-level campaign finance reform, replacing multilayered first past the post, and probably reducing the power of the presidency so this new many-party Congress actually matters rather than so much power in a single (and thus winner takes all) office.
Edit: as another unrepresented belief, if I think Israel is a geniciding state that deserves no international support, well, too bad, the center of both parties if firmly in the pockets of pro Israeli interest groups.