In democracies, you sometimes can see authoritarians being elected. Current situation in the USA is one example.
Not really. The US situation is engineered so only two parties ever get in, and are practically impossible to remove. Wait several years and the other lot will get in.
Even with Trump we see a lot of policies and directions that the Democrats have pursued previously.
You have much better (concrete) examples in South and Centeral America, e.g. Venezuela & Nicaragua, but there are plenty of others.