In 2016 Trump supporters were called “Deplorables” and other unflattering names. This was a major contributor to the “shy Trump voter” phenomenon that “most” polling missed which resulted in a major loss in public confidence for polling flowing the election.
In 2020 people who supported Trump or espoused conservative values out of step with “Woke” culture found themselves being “canceled” or “doxed”. This led to “hidden voters” that “most” polling under counted, therefore Trump support in key battleground states exceeded expectations
Now that the Biden administration has essentially classified “MAGA Republicans” as a threat to democracy marshaling federal law enforcement to focus on them. This move has created a new type of voter that will be even harder to poll or even estimate.