I think she's mentally ill. That has to be the only explanation.
This is often said as a joke but I legitimately do have mentally ill friends who are far less unmoored from reality than this woman. I think mental illness is a part of the picture perhaps but it's a very insidious combination of things in America which is causing an increasingly large number of people to behave like her.
I'm very close to someone with multiple comorbid dissociative and psychotic conditions and she's nowhere near as far gone as MTG. Her oddest views are all just speculative Christian theological concepts. Mental illness is really no excuse.
I find some of her beliefs like "forest fires are caused by secret space lasers built by the jews", " "Zionist supremacists are conspiring to flood Europe with migrants to replace the native white populations", "Seth Rich was murdered by MS-13 henchmen on behalf of Barack Obama" or especially "it's perfectly fine to harass school shooting survivors because they're crisis actor hired by Nazijew Jewrge Soros" and "I like posting memes about murdering my fellow Representatives because they happen to be commie traitors" to be a little more worrying and/or weird than whatever fundamentalist christian weird crap she may believe in