As the states should have started doing when the Constitution was ratified, the states need to require all candidate voters to pass a basic Constitution test before being allowed to vote, such a test emphasizing the federal government’s constitutionally limited powers.
Otherwise, corrupt politicians who seek election to federal office will continue to take advantage of winning votes from immigrants and the decendants of freedmen who have never been taught about the federal government’s constitutionally limited powers the way that the Founding States had meant for those powers to be understood. Such a test would hopefully help immigrants and descendents of freedmen to be on their guard with respect to campaign promises from federal candidates which are based on constitutionally nonexistent federal government powers.
Such tests were tried and struck down.