Yeah, but Johnson survived not because anyone supported him or his policies, rather he survived because politicians wanted to protect norms. Times have changed considerably since then. I'm pretty sure politicians are far more interested in destroying norms. So I wouldn't count on the Johnson Conundrum happening again. People are out to break those norms nowadays.

Sure, the country survived, but did it return to the political status quo? Last I checked, presidents are still allowed to use the veto on policy proposals they disagree with, rather than it's original purpose as a constitutional defense tool.

Rome survived when their political structures fell apart in the first century BC too. Does that mean you would be equally happy to live under the thumb of Nero as you would to live in the free and open democratic society of the second century BC republic?

FDR was probably more of a norm breaking president than Johnson.

The jury is still out on whether or not the US will survive.