Raise it to 26 and require that you paid taxes the previous year.
Better idea: Raise to 26, and you pay no federal taxes until the same age. No taxes, no votes.
Now that I think about it, TECHNICALLY, under Obamacare, my “children” are still able to stay on my insurance until they are 26, so I think you are right!
No voting until you are 27, and ONLY if you paid taxes the year before!