At this point, my claims are based on the potential effects of executive orders, policy goals, and past statements. If you're still a Trump supporter, I'm wasting my time, because you obviously don't care about the idea of evidence, truth, or symptoms of authoritarianism, but here is some info off the top of my head.
1) advocates for torture, said that he would be open to the idea of killing families of terrorists, bans refugees that go through a very thorough, years long process to get here and are victims of the people that we are intending to ban, talks about illegal immigrants like they are subhuman, labels the entire media as scum and similar because they don't constantly adorn him,
2) repeated claims of false voting fraud is a set up to take away voting rights, eminent domain for the border wall (more of a property right), Justice Dept proposing harsh felony charges for journalists do their job covering a protest/riot (more of a freedom of press), advocated for Muslim registry (violation of freedom of religion).
3) executive order to go forward with the Dakota Access pipeline and I will not be surprised if those people are harmed by the law enforcement autorities. Trump clearly is a sociopath and will not care if those people are harmed. Any time he says that he is the president for all people or he has a big heart, it is unsettling to hear because you know he does not truly mean it. I'm sure he never laid awake at night thinking about how he may have hurt someone, like many of us have.
It all sounds like a setup for an authoritarian regime with a playbook straight out of 1984. You give me this "enforce the laws and law and order" crap, but that is used an excuse for governments to strongly enforce their power while trampling on the rights of the people. Black folks during the civil rights movement were very familiar with that type of rhetoric.