Yup, both early voting and absentee balloting make this possible.
why do we have early voting anyway?
Absentee should be for the few who work out of state and the military etc.
There should be a system like the driver license .
If a cop pulls you ten he knows on his computer if you were pulled anywhere in the country .
Why not have a system which tells a central computer that you have voted and where you are registered and if one tries to vote in another state of which many do in my state then it raises a flag and the penalty should be prison for a good long time