If a person had a durable general power of attorney for another person as a result of that person being disabled but not incompetent, would it be legal to sign a ballot and cast a vote on their behalf?
There is another question with good answers about proxy voting for someone who is mentally incompetent here: POA & Proxy voting
However, this scenario is the opposite. It this case the person is able to communicate their preferences, but unable to fill in the marks or sign their name to a mail-in ballot. (the only option in Washington State)