If this was a Westminister parliamentary system then the 2 party duopoly would fail. As it stands the only path to political power is to build coalitions based on a demographic and ideological basis. In the parliamentary system you can vote for your conscience based on a narrower platform and the party then turns around and forms coalitions with other parties that are different. In the US these coalitions are formed before an election and you have to live with other platforms you may not agree with but the need to win supersedes purity. The echo chambers today are readily available leading people to think that they have massive numbers behind them because they communicate with like minded people. I am not sure you can say this system is worse than others out there that often yield unwieldy coalitions that collapse easily if one party pulls out. Israel, Italy, and Japan are examples of this coalition building mess that you get with multiparty. It's easy for the vocal part of the party to think they are getting shafted, it's just that they ignore the other part of their grand coalition and the votes they have.
Talk about clueless...
, BROTHER!

I'm very sure they know it's about to happen, but again, it takes a lot of concrete evidence to try to pin that on a party or nominee, and there's very few outlets, if any, that brave enough to put it all together and then tell the New Yorkers.