Final answer:
Non-citizens, non-residents, individuals under 18, those deemed incompetent, current inmates, and some felons and ex-felons are not eligible to vote or become citizens of the U.S. Paths to citizenship are available for non-citizens, while debates exist on the fairness of voting right restrictions for felons.
Step-by-step explanation:
Individuals who are NOT eligible to participate in elections or become citizens of the United States include non-citizens, non-residents, people under eighteen, those deemed incompetent, current inmates, and in some states, felons and ex-felons unless pardoned or their rights restored. The restrictions on citizenship and voting rights are in place to maintain the legal and civic framework of the nation. However, the implementation of these restrictions can be controversial when they disproportionately affect certain groups, leading to debates about the balance between electoral integrity and the right to vote.
For non-citizens looking to participate, a path to citizenship through a process that includes fulfilling residency requirements, demonstrating good moral character, and passing civics tests among others, is available. This process is realistic as it ensures that new citizens have a basic understanding of the U.S. government and are committed to the country. Conversely, the barriers to restoring voting rights for felons can be seen as unrealistic or unfair by those who argue that once a debt to society is paid, full civic participation should be restored.