Vote fraud is worse than murder or rape! It is not a crime against an individual it is a crime against everyone. Furthermore it’s primary purpose is to put people in power who will murder and rape multitudes.
The casting of an unlawful vote offsets and therefore negates a lawful vote. The effect is exactly the same as if the unlawful voter stood outside a polling place with a gun to prevent the casting of a lawful vote or stole and destroyed ballot boxes. There can be no greater crime against the republic and the citizens it represents and should warrant no less a punishment.
Voting and elections is administered at the local and state level. Would you like the Feds to take over all elections, including local and state elections? After all, liberals from other states would love to directly influence elections in conservative states and jurisdictions.
Penalties for voter fraud can be handled at the state and local level.