Not to mention, you can do the opposite: you can destroy your "wrong-minded" family member's ballots to prevent them from voting.
You can always still go vote in person at a polling center, even with all-mail voting they always keep a few open just in case someone loses or spoils their ballot.
They'll record the vote provisionally just to make sure you're not trying to vote twice, and once it's clear no mailed-in ballot arrived it gets counted.
https://www.brookings.edu/articles/how-widespread-is-electio...
Don't know about Colorado but many other states have been sending ballots to dead people as well as people who are not resident anymore. The potential for fraud is huge
https://apnews.com/article/2022-midterm-elections-voting-gov...
https://www.rmpbs.org/blogs/news/colorado-noncitizens-deceas...
Is your claim that the social security administration sends a death notification to the deceased person's voter registrar?
“we get information when Coloradans pass away from two spots… the Department of Public Health and Environment and also the Social Security Administration.”
https://www.brookings.edu/articles/how-widespread-is-electio...
https://www.cnn.com/2023/08/06/us/oregon-drivers-pump-own-fu...