Is it legally impeded? I know there are ballot requirements, though I don’t know what they are. My impression is it has always been about exposure. Republicans and Democrats get the exposure; third parties do not.
Just remember the weird rules Virginia has for our own well-known candidates to get on their flippin’ ballot, and you’ll see just the tip of the legal-impediment iceberg that has been thrown up in the parties we do have, and that will give an idea how hard it would be to make the nation NURTURE alternative parties rather than MAINTAIN THE POWER of only 2 parties.