What did the framers call the least dangerous branch of government?

The framers of the Constitution, though unified in purpose, were not one in political philosophy. Many feared the rule of the "mob" hence the election of the President by way of the electoral college and representative democracy. These men would have more faith in the executive branch (albeit a weakend one). Others were much more democratic. Those, like Jefferson, believed that power came from the consent of the governed. He also advocated the rural over the national. Because of this, he would have felt that Congress, with its connection to the people (constituencies) and balance of power, would make it the least dangerous, though it signs the checks.