I don't think it's that straightforward. It's hard to vote for something that doesn't come up for a vote. And it doesn't come up for a vote if the right people don't want it to come up for a vote.
Logically if the US electorate cared even half as much about [topic x] as they do about guns - candidates would care too and "democracy" would follow... no?
(I'm not bashing the US, just taking gun control as an example where a passionate popular view is reflected democratically)