I think a democracy can exist long term, but it requires an educated voter, which we lack on a widespread basis.
I know ANY barrier to open voting is considered evil, but there are (seemingly lots of) people out there who literally have no idea what or who they are voting for. Heck, we have people voting who literally don't know how the government works, and/or cannot name the current (or last, etc) VP. And their vote counts as much as yours or mine.
Allowing anyone who can fog a mirror to vote means we have a largely politically-uneducated active voter base. And we end up where we are today.
But as I said above, ANY barrier to open voting is considered evil, so no, our democracy will not survive - ours will eventually fail.