So "Please consider that supreme courts may also limit the power of the Bad Guys" is clearly false, because when the Team X has power, they will make sure Team X is in every branch of the government, and their justices will decide whatever the executive branch is doing is very kosher and constitutional, as long as it's their team.
In the end, the system can only hold as long as even "Bad Guys" are good enough that they're not willing to break the system from inside. You keep electing the Real Bad Guys, the system will fail. Checks and balances aren't magic.