They're indicative of a collapse of consensus on the part of society. It could well be argued that prior to our current political era, especially in the US, that the political domain was largely constrained to a discourse on cultural aesthetics, wherein the Democrats and and Republicans argued over trivialities (on a broader national, not individual respect) such as abortion, marriage, and immigration, while they operated on an implicit consensus concerning foreign policy, and had a functional stalemate in terms of the size of the state, farming out many of their policy decisions to thinktanks, corporate donors, and well-established bureaucrats within our regulatory bodies
America's role as international security guarantor, its trade policies, and its government's role in domestic affairs was never really up for debate, and it only really changed stepwise in a stochastic manner, responding to situations and incentives day-by-day with no conscious consideration to the role of America or its state on a broader scale.
What we're seeing now, is large portions of the population coming to realize that that existing bipartian components of the political consensus - which I believe to be a legacy of the cold war, no longer serves their cultural or economic interests.
This process is naturally fractious, chaotic, sometimes violent, and full of dirty tricks, because politics isn't just about flavor of the month policies anymore. We're in the process of reinventing who we collectively are, and what we want to be. As a result, we're running across real, fundamentally irreconcilable political and moral differences that have been buried for decades, as well as confronting the failures and controversies of our past.
Many of those fundamental agreements settle neatly along class, racial, and professional boundaries. Others, not so much.
Science denial and anti-intellectualism is the natural result, because much of science communication has become a carrier mechanism for policy prescriptions predicated upon society operating under a specific ideological consensus, when in fact someone of a different political persuasion might objectively consume the scientific data and come to a different policy conclusion based on the same data.
For the less educated, who encounter proposals from scientists they consider to be politically unworkable, and which might rightfully be considered manipulatively framed, it is easier to reject entire specialized fields of research out of hand than to investigate further and attempt to conceive of alternative proposals because they lack the tools to engage with the information effectively to begin with.
All of this is messy, but it constotutes a real political dialogue on the part of society.