It's truely a team effort the Republicans and Democrats are the ratchet effect manifested.

The FPTP system ensures you will only get those two choices so if you want to effect change its probably easiest to do it at the primary level.

People always say 'progressives can't get elected nationally' or whatever forgetting FPTP ensures things will swap back (under the assumption that one side doesn't flip fascist before that happens, big assumption in this climate I know) because eventually people will tire of the person in power and either vote for 'change' or stay home.