I have seen much going around on social media on the SCOTUS ruling on Arizona and the motor voter laws. Yesterday, the court came out with a 7-2 ruling that Arizona couldn't add additional requirements to the federal forms for voter registration. Arizona wanted to require additional paperwork proving American citizenship.
On the face it seems silly that the court would come out against this. But it isn't silly. It is completely Constitutional. The federal government gives states money to cover the costs of all seats that are held in the federal government. The Constitution says:
The Elections Clause, Art. I, §4, cl. 1, provides:
“The Times, Places and Manner of holding Elections
for Senators and Representatives, shall be prescribed
in each State by the Legislature thereof; but the
Congress may at any time by Law make or alter
such Regulations, except as to the places of chusing
Now that sentence about Senators is no longer valid since the 17th amendment made senators also subject to direct elections. But the point is the federal government absolutely has the right to decide how registration is done for federal elections.
The court also has given Arizona a pathway to make changes to the Motor Voter form. Arizona can, if the so choose, go to the Elections Assistance Commission and ask them to make changes to the federal form. While that is highly unlikely under the current administration, if they don't like the result, they then can take it to court.
The Court did not rule on anything other than could a state require additional information on a mail in federal form for registration. Arizona is free to require additional information on state forms. Those registration rolls can be cross checked if they so choose to do it.
The main point of this ruling is that the court did exactly what it was supposed to do, follow the constitution. You may not necessarily like the outcome, but the federal government has the right and the responsibility to set rules for how federal elections are set up. If we want changes made to include more safeguards for proof of citizenship, the avenue to do that is there. The State of Arizona doesn't seem to be shy about pursuing their options, so let them lead the charge to put more safeguards into place.
You can read Scalia's opinion here.