No reality perceived by humans is perfectly accurate, for the truth is infinite and the mind is finite. At the same time, no reality perceived by humans is completely incorrect. What we have are realities that work better or worse.
I do not claim that we can measure the verisimilitude of any perception of reality, although I do claim that there does exist an objective reality.
What we can believe is that any given statement about reality can yield better or worse results when applied. For example, if I declare that gravity pulls things down from the surface of the earth, then I can safely predict that, if I place a book on a shelf without proper support, it will fall to the floor.
That's the metric we can use: utility. The closer our beliefs are to Objective Reality, the more likely it is that our beliefs will lead us to make decisions that yield our desired results.
To summarize in two words: Truth works. This applies even with highly complicated phenonomena, if our perception is "close enough" to objective reality.
My point was that the Republican perception of reality is so far removed from Objective Reality that it fails badly. Republicans decided that climate change is a hoax, and therefore took no action to resist it; therefore, climate change has grown worse. Mr. Trump decided the Covid-19 was not a serious threat, and as a consequence, 300,000 Americans have died. Mr. Trump claims that his policies have improved the American economy, when over the long run he has wrought great damage to the economy. Despite his claims, he has made America weaker, not stronger. That's the result of playing fast and loose with the truth.