Not so; on many issues, the country as a whole (its citizens) knows what it wants but the parties and duopoly can't deliver it because of how they're structured.

For example there are improvements to healthcare, taxation and financial regulation which a supermajority of citizens would agree with, but the current system cannot/will not deliver. These improvements do not particularly align with either party's agenda.

Another example, closer to people here on HN; merit-based immigration. Support among citizens is broad and I am guessing it would be a supermajority; however more politically active and powerful people in the US on the left and right oppose it.