Any system that isn't a very narrow form of representative democracy requires a massive re-write of the constitution. That is not a reason to not consider them

Any system that isn't a very narrow form of representative democracy requires a massive re-write of the constitution. That is not a reason to not consider them. In a delegative democracy, decision making is a lot more fluid than in the current system. You can buy or coerce someone for one specific issue, but the impact of that will be lower than buying a Senator. That makes intimidation and bribery less effective from the onset, and it can be mitigated further depending on the exact implementation. Either way, just like in the current system, there can be checks and balances to reduce the likelihood of it happening.