It is against the law to STEAL or MURDER. Why can't it be against the law for a citizen who doesn't vote? Charge big fines and penalties. You can't put the in jail but you can make them pay!
That's weird ... I had a couple blank lines then an answer, in my original post ... But it doesn't show up.
Anyway ... I would be fine with requiring people to vote.
I wouldn't use a fine or jail time, though.
I'd say you have to show proof of voting in the last election, to get any benefits from that level.
EG: To get any benefits from the federal government, you had to vote in the last federal election.
To get any benefits from the state government, you had to vote in the last state election.
The only exception I would grant, would be in cases where it was impossible to vote. Such as being in a coma.
Being out of town, or on vacation? Not good enough.
Some African country just had an election "do over" and people cancelled trips so they would be able to vote the second time.