Hmm that's interesting. Who told you that? The US just had a republican president. Many states have had republican government for decades. Do we see this happening? No. Instead here we are talking about a real and tangible event, largely championed by mainstream democrats.
If you think the average republican voter would support enacting "fascism [to] tear down the tenants of democracy in the US, while siphoning as much money and power to big business and the upper classes as possible", then I suggest you talk to some more. You may be quite surprised.
Regardless, I think this is a major pitfall of the two party system. What you say certainly has truth. What I say has truth as well. However discourse usually devolves to attacking the extremists in each group and no real discussion can be had. I am optimistic about the future. Have a nice day.