Thanks for all of the answers. Regarding my first question, if the people of a state vote for a senator rather than the legislature of a state voting, the power still belongs to the state, it seems to me. I'm still not getting why one is operable to the other.
It's very much different if you understand the nature of the government that the Constitution created.
We all love the checks and balances moniker. It is partly religious in our political lexicon. But there is a reason for that. And we've hit on it numerous times here. The founders did not want any singular person (the President) to weild so much power that we became an imperial republic. This is obvious to anyone that has studied the office and the powers that it was given. The bulk of the actual real power of the government comes from Congress in a bicameral legislature. But just making the entire Congress the sole power base was a problem too, because without an executive function the daily operation of the government wouldn't work. A singluar legislature that is only answerable to the people is too democratic. The founders weren't democrats. They were republicans. Small R, small D. They didn't believe in the total absolute unchecked power of the people even though some considered the people the King. There had to be a check on them as well.
Further, the states that made up the country were entities unto themselves and would remain soveriegn in the new system. The Articles of Confederation failed because the national government had no power. But the Constitution wasn't going to abolish states either. The checks and balances of the entirty of the federal government resolve to the states either separately or together through the Senate. The state as an entity is a being within the confines of the government. So the founders had to figure out a way to balance an executive, the states, the people, the legislature, the judiciary. They had to do this knowing full well how England had it set up and how the AoC failed miserably. The Continental Congressmen who were at the convention knew all too well the problems with just 13 colonies and a toothless commission at their helm. The federal government had to have power but not absolute power.
All legislative acts with reside in the federal Congress. That means that the federal Congress will be the supreme law of the land. But you can't do that and still have the states exist as sovereigns unless the states have a stake in the system. And you can't have that Congress be entirely democratic because the people while the King, are also a mess and the mob can't possibly be given the power to control the government without a safety net of checks and balances. The House is the people's body. The people have their voice heard there. Anything they want happens there. But to temper that they came up with the Senate. How the broke down their powers is massively instructive.
All revenue bills must come from the people. It's their money that is being used. And therefore the people get to make that call on taxes and duties and tariffs. The House must make that law. But not without a check. The Senate would have the sole power over treaties and the makeup of the executive department. Not the people. The people don't have a say in who the Cabinet is and what Treaty we enter into. The states as political entities do. This is important. The foreign policy of the national government would be checked by the states, not the people. The states will retainer their soveriegnty in the system as important actors. If it is simply left up to the people, well, we know what happens there. Look at federal mandates since 1913 to the states. The soveriegn power of the states has be diluded substantially. And that wasn't the intent of the system created and the mechanics of the system are broken as a result of th 17th Amendment.
The brilliance of the Constitution was not the checks and balances. In theory, given what the founders went through in the years leading to the revolution you know that they would try to limit the power of government. But the beauty is that they did it horizontally and vertically. Horizontally, the check system pits the Executive against the Legislature against the Judiciary where they each bounce off each other and call the other to the carpet through a procedure. Congress can't just pass a law, it has to be signed by the Executive. The Judiciary has no teeth unless the Executive enforces its dictates. It can't enforce those dictates without the money from the Legislature. The Legislature can't pass unconstitutional laws or the Judiciary will strike it down. Horizontally the system works because all three main players check each other and their epicenters of power grow and shrink depending on the topic at hand. It works.
Vertically, the checks start with the people, to the states, the federal government. The people must be heard and their local and state government is the daily government they will interact with while also being guided by the national government. The state governments are protected as republican entities meaning that their sovereignty must not be abolished and the national government is tasked with protecting the states and their soveriegnty. The national government has the supreme law but that supreme law has to first be ok'ed by the states and the people combined. Vertically it works because there is no imperial national government where states are mearly border designations, the people are heard at all levels but tempered, and the national government needs them both to function.
The vertical balance was destroyed by the 17th Amendment. Now there is no people to state to federal. Now there is just people to federal. Sure the states still exist but with the Supreme law coming from the Congress and the Senate no longer beholden to the states but to the people, the Senate mimics the House in its fickle nature they just serve a few years longer. The state legislatures stop being the incubators of law and become servants to the federal Congress who can now impose laws and regulations on the states that they couldn't do before without the states accepting them. Just as we discussed previously the need for beauracracy, in this setup the state was the beauracracy to the federal government. The fed can't possibly know how every single law effects every single state and then every single person, but the states have a better chance of doing that and working the federal system within and throughout the state system and vice versa. Now we have state's that violate their own state constitutions because they must abide by federal dictates and that in turn creates turmoil at the state level and results in the people not getting the government they want.
The horizontal check has also been damaged, because the legislature doesn't exist the way it was intended to anymore. Now the people have a say in treaties and cabinet selections. Now the people run the entire legislature. We have effectively created a unicameral legislature through the 17th amendment but in doing so we keep making it follow the rules of procedures of a bicameral legislature. And the result is that Congress gets hated more and more and more by the very people that want more and more democracy in spite of them not knowing what in the hell they are talking about. The Senate is a uselss organization now, except that it must exist through the Constitution. The games that House members play on the floor of the House have now become the same games played in the Senate. They are one body broken in half not to spread power anymore but because we came up with a bad solution to a problem that didn't exist.
The mechanics of the national government required the states to be entities in the vertical and horizontal checks that the system created. We took that out and as a result yeah we became more democratic but the republican Constitution wasn't created nor, I would argue, able to exist within democratic systems. There is really nothing democratic about the constitution. The President is a republican office. The Supreme Court is a tyrannical office. The Congress fights daily between its republican makeup and its democratic roots and the system clashes with itself over and over and over and over again. It's no different that taking a washer out of a sink faucet. Sure, the water will flow, and you might not even notice any problems. But there is a leak somewhere that gets progressively worse over time until the sink is rotted out and the cabinets are destroyed by water rot. But hey, without the washer the water came out faster.
The original senate was a perfect body in concept within the confines of the Constitution. The 17th Amendment bastardized the constitution more than any other amendment and it has resulted in the functional capacity for our national government to work with all the power bases in this country that the Constitution protects to be severly hampered. Now fatguy will argue that isn't a problem and that more democracy is good. He could be right. That isn't the point of the argument though. If you truly want a democratic legislature then the correct "fix" to the "problem" isn't the 17th Amendment, its the elimination of the Senate altogether and the repeal of half of the Constitution so that the mechanics of the government can function. If you are going to take the washer out because you want a better water flow, take the entire sink out and get one with a bigger valve. You will save your cabinets, floors, and country.