The word cult is not in the Bible. So it makes it hard to know what it really is. If you read the definition a relatively small group of people having religious beliefs or practices regarded by others as strange or
sinister.
That would have referred to the early church, so that is a rather poor definition. Also, why does the number of people in the group make a difference? There are a lot in the JWs and I would classify them as a cult, same as the Mormons, same as Islam, same as FreeMasons. I regard their religious beliefs as sinister. As for those that are "strange" that would include many others.
Then there is the other definition a
misplaced or excessive
admiration for a particular person or thing. Well that is simply idolatry. I would argue that everyone in the world is idolatrous. They have an excessive admiration for money, or people. Think of all these ones going to some sporting event and acting like fools because of some "super star". Same thing with musicians, artists, politicians, etc.
Why could so many people be led astray by the MSM, it is because they have misplaced admiration for talking heads on the TV like Fauci.
So then, is MAGA a cult? For the most part. How about the Democrats? Yep. How about Americans -- definitely. Most, not all, but most. There are probably around 1-3% of Americans who are not idolatrous at all, but the rest are. They put up idols in their home worshiping pagan religious idols and have excessive admiration for people and things.