Actually, it's entirely relevant under the Necessary and Proper Clause (Article I, Section VIII, Clause XVIII). But you wouldn't know that. It states that government entities have the duty of instituting laws that are necessary and proper, and since there are laws making missing court a federal crime, that makes it relevant. That common violation is a crime, and since the Constitution literally states it is not only the right, but the duty of government to make necessary laws, his criminal record is the most relevant it can be.