An individual's understanding of the world is shaped exclusively by the signals produced by their 5 senses. Intelligence governs an individual's ability to interpret those signals and draw further conclusions from those interpreted signals, but if that individual is fed a constant stream of bad yet internally-consistent data, correct application of logic and reason will lead that individual to objectively incorrect conclusions. Further, human beings aren't perfectly rational machines capable of processing the utterly overwhelming amount of signals we are exposed to at any given instant, rather we develop blinders to focus in on specific signals and we develop heuristics to reach decisions without processing all possible signals. I haven't read every whitepaper put out by every politician I've ever supported, nor has 99.9999+% of others, but we still support politicians because of our heuristics and blinders. I prefer forming my opinions from whitepapers, source documents, and a rigorous analysis of a candidate's behavior, but ultimately a heuristic I rely on is the opinion of other people or institutions that I trust, like the New York Times, the Economist, Ezra Klien, Matt Yglesias, Raj Chetty, etc.

I've decided that I don't like believing incorrect things, so I've thought a lot about epistemology and embraced a mixture of pragmatism and empiricism (where possible). I try to independently verify suspicious claims, but it took me a long time to become a competent data scientist, I'm willing to spend far more time searching for good data/signals and analyzing them than most other people, and I still can't be informed on everything which necessitates reliance on sub-optimal heuristics. Most people don't even attempt the rigor I aspire to, preferring a tribal epistemology, where they outsource opinion-forming to the thought-leaders of their tribe. If those tribal thought-leaders are telling people things like

* "Hillary Clinton is running a pedophilia ring out of the basement of this pizza restaurant" or
* "COVID-19 is a librul hoax so don't wear a mask or embrace any hard-won public health advice" or
* "Joe Biden's landslide victory isn't real, and even though we can't prove it, despite the fact that electoral systems are designed so that malfeasance would be easily detectable, you should ignore reject the result of a DEMOCRATIC ELECTION, EVEN IN STATES WHERE THE OUTCOME WAS CONFIRMED BY A HAND RECOUNT"

you'll see behavior from individuals in that tribe that's consistent with the signals those individuals perceive, but the behavior won't produce the expected outcome, because the signals don't reflect reality. Instead, it will produce mayhem, death, destruction, pain, and loss. This is empirically undeniable.

TL,DR:
Democracy depends on the votes of people. People form opinions only from the information that passes through their senses and into their mind. Garbage in, garbage out. It's possible to solve problems through rational analysis of sufficiently accurate models of reality, but models that don't reflect reality can be extremely, devastatingly destructive. If the signal "Donald Trump actually won the election and it is being stolen from him" was an accurate description of reality, it would rational to use violence to repel the usurpers trying to steal your country. But that signal is false, and spreading that signal both is eroding belief in democracy among the communities where enough members embrace that false signal, and it will in lead to unjustified murders.