This happened with the mass exodus from Reddit to Voat of r/the_donald and similar, and I absolutely can see it happening here. Voat became host to a ton of toxic communities.
And because of that, it's going to push more orthodox people people away from the site towards Twitter in a self-reinforcing loop.
The plan for the site to get a broad range of opinions (in this case, the bounty of $20k for a prominent liberal) seems doomed as a result.
Still - hopefully the founders have learned from Voat and have plans in action to stop it before it gets too stuck in the cycle. The bounty is an interesting idea, though I don't think it'll be strong enough to break the perverse social dynamics involved. More competition with Twitter is a good thing.