I say all the time that our votes don't count. First of all in the general election, we vote, then politicians vote for us. Makes sense, right? Now in primary, our votes don't count if the delegates aren't bound to the candidate. Also if it goes to the convention, the delegates can vote for anyone. That includes people not even running. They could elect your garbage man if they wanted to. The whole system is set up so politicians can rig the elections.
To add on top of that: many states are all-or-nothing. 51% vote Hillary, 49% vote Bernie, and they give all the votes to Hillary. They literally take your vote and put it towards a different candidate.