It's one thing to say that this is a federal issue and must be handled by a federal court, but if states can't decide who is on their ballot in this instance, what authority allows them to do so ever? Different states have different rules with regards to which candidates and how they get on the ballot.
Federal elections should not be run by States if States are going to be limited seemingly at random on what they can and can't enforce. What happens if a 20 year old runs for president? Are states allowed to say no to that because it's in the Constitution, or would Congress need to clarify that as well?