I hate to quibble, but the Founders said our government would only work FOR a moral people. Their emphasis, as yours, should be on us and not on those elected. We can only keep them in check with limits.
But again, you mistake what the Founders were saying.
Doesn’t that also mean that only moral people should be in office, so as to prevent those abuses that oppress the people? I interpret what Franklin and Adams say as applying to those in political power as well.