The USA won’t become a one-party state, but by gerrymandering some states the House of Representatives could very well become a circus, and the votes of all the other states will become irrelevant.
The first reaction will be to withdraw into fortress Massachusetts. Since the Republicans are all claiming they are doing what they can because of “states rights,” our state will decide which of the crazy things they will try to do we have to follow. Biden is still President, so unless there are huge swings in the election he can veto stuff and it won’t be over-ridden. There won’t be new laws. They may try to impeach Biden, or they may try to investigate Hunter Biden or even Benny Thompson.
The real damage will be to the election process, and how those states will continue to pass laws that make things that are illegal now, legal in those states, including Jim Crow-type laws. Perhaps we won’t pay Federal taxes in protest. It depends upon how crazy things get.
What they do will either lead to the end of the current Republican Party or the end of a coherent government in the US.
I am hoping that a few indictments, that include Republican members of Congress, will be enough to wake people up.