Who are these interest groups? My understanding is that pre-Clovis is completely established beyond any semblance of reasonable doubt, so they're 30+ years behind the times.
From what my archaeologist friends in North America tell me, the interest group is modern native Americans. They are the direct descendants of the Clovis culture.
Clovis-Americans have certain unique rights based on legal theories that their ancestors were the first human occupants of the land, which would be weakened or voided if substantial scientific evidence established that they simply replaced a prior human culture. Due to a perverse set of incentives, native American interest groups use these unique rights to actively interfere with archaeological research that might undermine their claims to being the first occupants of the land. While it has not stopped pre-Clovis research, it has greatly impeded it.
While the scientific evidence strongly suggests a pre-Clovis people, the legal theories and legislation that presume this is not the case are still active. These are evaluated on a case by case basis currently.
I'm a (formerly working) archeologist. Native American land claims are horrifically complicated and way beyond my knowledge, but I'm not aware of anything that's legally based on the scientific consensus about the earliest inhabitants of a specific area. Instead, the term you'll commonly find used is "aboriginal title", which basically just means "we've been here a long time". It's as deliberately vague as it seems and isn't affected by pre-Clovis at all.
NAGPRA has run into complex issues with ownership being unclear when we've found ancient remains, but that doesn't mean people are rejecting the concept of pre-Clovis. It's a separate set of issues entirely.
I'll mention that many indigenous belief systems do incorporate aspects of "we've always lived here" when that's clearly not what the archaeology says. Most such people accept both sides as belonging to separate things in my experience. It's not all that different from Christians who believe Exodus happened for example. The scientific consensus isn't really relevant to that belief and that's fine.
> Clovis-Americans have certain unique rights based on legal theories that their ancestors were the first human occupants of the land
Please point to these rights and legal theories. Do you just mean NAGPRA?
As far as I know, whatever legal rights any native American people have in the Americas at this point in time are based purely on them being here when Europeans arrived near the start of the 16th century.
Whether they had been the occupants for 400 years or 40,000 years wouldn't make any difference to the treaties that were signed (and generally abrogated).
As of 1995 more than 50% of people who identified as Indigenous preferred the term "American Indian".[0]
It's interesting how people outside of a group can erase that group's identity just by taking away the name that they use to define themselves. Any politically correct American has to say "Native American" or use the even more generic term "Indigenous People" while the majority of the people being referred to understand themselves to be "Indians" or "American Indians". Hundreds of years being known as Indians and having that taken away by scholars and academics. It's a sad final twist on an exceptionally sad story.
What is the correct terminology: American Indian, Indian, Native American, or Native?
All of these terms are acceptable. The consensus, however, is that whenever possible, Native people prefer to be called by their specific tribal name. In the United States, Native American has been widely used but is falling out of favor with some groups, and the terms American Indian or indigenous American are preferred by many Native people.
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This also provides a good overview through a series of personal viewpoints:
I don't get where this "has to" business is coming from. If they want to be called Indians or American Indians, then I'll call them that. There's no need to get wound up.
Clovis-Americans have certain unique rights based on legal theories that their ancestors were the first human occupants of the land, which would be weakened or voided if substantial scientific evidence established that they simply replaced a prior human culture. Due to a perverse set of incentives, native American interest groups use these unique rights to actively interfere with archaeological research that might undermine their claims to being the first occupants of the land. While it has not stopped pre-Clovis research, it has greatly impeded it.
While the scientific evidence strongly suggests a pre-Clovis people, the legal theories and legislation that presume this is not the case are still active. These are evaluated on a case by case basis currently.