Since the Republicans are trying to get Libertarian candidate Gary Johnson taken off ballots in key states, then the Democrats should do everything they can to make sure he stays on them. They can sell it as wanting to support a more open democracy and that their confidence in their ideas means that they have no fear of multiple parties.
And to be fair, here is a return strategy idea for Republicans: If the Democrats actually do something like this, then you should pump money into getting a Green Party candidate on the rolls/media exposure.
Like I said, they’re free ideas. If you’d like, you may use them without paying me anything or giving me credit. I have tons of ideas, so there’s no need to be greedy 😮