I don't really blame them, or at least not primarily.
They're just desperate and frustrated and looking for someone or something to blame for the fact that what should be a great nation is instead a festering cesspool of greed, corruption, violence and stupidity. Like most, they won't or can't consider the part they play in that, so they look for some "other" to blame.
There is actually an "other" to be blamed - the wealthy and politically powerful few - but most of American history, and human history for that matter, has been built around establishing and protecting the privilege of those few, most often by manipulating public sentiment in such a way as to direct anger and frustration away from them and instead towards others of the common people.
So they're really just the latest in a long line of people feeling wholly justifiable anger and frustration that's been misdirected by self-serving shitheels. I guess they're rightly faulted for failing to recognize that they're mad at the wrong people, but really, that's true of far too many people.
Now all that said, on a personal level there's almost nobody that fills me with more rage and disgust than the bigoted right.