The rethorical tactic of referring to every single statement as a "claim", without discriminating between proper claims and observations, deductions, hypothesis, theories, quotes, etc..
In particular, by conflating merely speculative statements (such as hypothesis and theories) with conclusive ones ("claims") it presents opponents' positions as being more extreme than they actually are, which makes it very useful as a strawmanning tactic.
Moreover, since (different from other kind of statements) claims cannot be ascertained by mere logic/rational means, but only through direct evidence and source credibility, treating everything as a "claim" implicitly removes any need for rational debate from the equation, reducing the entirety of human knowledge to a mere issue of sources and authority.