All due respect, I'm curious as to what these signs actually are for Trump. Everything I've seen and heard has been horrifyingly taken out of context -- "dictator on day one" and "you won't need to vote in four years" and "he'll prosecute his political enemies", or exaggerated past the point of recognition, like "he tried to steal an election" or "he wants to put journalists in jail".
Under the Biden administration, we have seen actual criminal charges against Trump. Not theoretical, not threats, not innuendo, but actual criminal charges for trivial administrative offenses. We have seen extensive media collaboration with the administration (and the opposition when Trump was in office) in an attempt to distort Trump's words to portray him as being dangerous.
I do not agree that the US, under Harris or Trump, is at any risk of becoming an authoritarian nation. The "signs" here from both sides are all imaginary trivial things and political rhetoric. But if the watchword is "any signs" then I've got to say that I don't see how you can vote for anyone but Trump.
My forlorn hope is that people who think that Trump represents a threat of authoritarian backsliding can, in four years, revisit their assumptions and realize that the markers they have chosen to represent that threat are all wrong. They're just incorrect. Update your priors.