The US government, like US elections, operate at a remove from the actual citizens. When it comes to deciding who will be the nominee of the party, delegates aren't legally obligated to vote the way they're told. For a long time, neither was the electoral college although many states have changed their own rules to require it. That's why we refer to our government as a republic, with representatives voting on behalf of their constituents but not necessarily as their constituents tell them to vote.
The US government, like US elections, operate at a remove from the actual citizens. When it comes to deciding who will be the nominee of the party, delegates aren't legally obligated to vote the way they're told. For a long time, neither was the electoral college although many states have changed their own rules to require it. That's why we refer to our government as a republic, with representatives voting on behalf of their constituents but not necessarily as their constituents tell them to vote.