That actually makes it a much more difficult question. Without knowing how robust a democracy our hypothetical country has and how its government is set up, it's impossible to say which is the lesser of the two evils.
Though honestly, even for the United States, I'm having trouble choosing between them. They're both kleptocrats, so Trump's main selling point is that he's probably too incompetent to actually dismantle the democracy. Still, incompetence cuts both ways. From an international perspective, Putin seems to be less of an unpredictable wildcard and could probably be trusted not to accidentally start a nuclear war in a four year period.
