Up to you, and how you do it. The person might be liable for taxes, but the human is not. The voting form is a person. It is one of your 4th Amendment protected persons if you sign it. It is liable for the State tax, but it never has to pay any. Why not? It doesn't earn any. To see that this is true, simply look up the definition of 'person. in the law. A man or woman is not a person according to the definition. There are a whole lot of things that people are not liable for because of what a person is. Of course, if you tell gov that you are that person, you just made yourself liable. https://redress4dummies.wordpress.com/ and https://redress4dummies.wordpress.com/wp-content/uploads/2018/03/office-of-person1.pdf

Taxation is an attribute of sovereignty. That over which the taxing entity is not sovereign is not a suitable object to tax. A State is not able to tax federal assets, nor can it tax purchases by the Fed governmt. All states are required to maintain a Republican government. Article IV, Section 8. Citizens are Sovereign in a Republican govt. IRS computer printouts of claimed income tax values without adjudication evidence are used by states to assess claimed taxes. The values are hearsay and subject to objection and challenge---but maybe not if the individual submits to an administrative review of the states' assessment. A Constitutional Right [Trial by Jury] cannot be destroyed by Amendment. If Sovereignty of Citizens can be destroyed by 16th Amendment, it is a coup. If a judge enforces a coup, it has violated the oath of office and voids jurisdiction.

What the AG's letter says is that registering to vote can be taken as evidence the signer is a resident in the state. In the same manner a driver's license may be such evidence. The AG does not say applying to vote makes the individual responsible for a tax. AG's, as well as judges, can be tricky with words.