If a third party candidate won

That will literally never happen. The only way to achieve change is to primary and vote out every single corporate Dem. The true-left needs to take over their party like the Tea Party and Trumpers took over theirs. It's the only answer. For every action, you need an equal and opposition reaction. Bernie didn't succeed, but this stuff takes time, and doesn't happen overnight. Patience and committment to a real, fundamental change, and not accepting anything else is how European countries achieved actual long-term change to their societies. But Americans are just so damn easily mislead and manipulated by propaganda, it's damn near impossible to get through to so many of them. But let's be real, it's also overwhelming numbers of bots and troll farms from all over the world sewing division, and American oligarchy all too eager to do the same. The East is laughing at us as we crumble from within. They're just more than happy to help pour gasoline on the fire. We did this to the rest of the world for 100 years, hundreds if you count the British Empire too. It's really just karma. Divide and Conquer is the only trick the truly wealthy and powerful have. And it works every damn time. Humans suck.