Democrats are lazy people, and lazy voters; having to get up and vote in person is too much for them. And Democrat politicians know it.
The mail voting is there because they are used to having everything mailed / shipped to them without them having to get up and doing things.
Mail in voting has been identified as the primary way to introduce fraud into an election from studies around the world. Advocates of it know this as fact. I was thinking yesterday, how can a country with the most advanced space rocket system in the world and spaceship have one of the most unsecured election processes in their system. It's a disturbing contrast of evolution in a society where we marvel at some aspects of it yet are in total despair in others aspects.
Precisely