Let's stop treating this as "maybe there's a way to convince people", understand that there is no way to convince some people, and instead just win. Win, and keep winning, and use those wins to eliminate things like voter suppression and gerrymandering, and then never lose again.
And even if your wildest dreams come true–if you win too big, the other side may turn around and say "democracy isn't working for us any more". If it gets to the point that a significant minority of the population (say 20-40%) no longer believes that democracy is in their best interests, democracy's days are numbered. Especially if that significant minority has a great deal of wealth, influence and power. It could end in the peaceful negotiation of a "national divorce"–and there are many worst ways it could end than that.
> the other side may turn around and say "democracy isn't working for us any more".
They do that already, whether it's true or not. That's not a reason to decide to lose.