You can be fair to someone whether or not they are in power or out of power. This is the same pernicious argument that excuses anti-white racism because “blacks aren’t in power” in general, even though a black gang against a single white person in a dark alley has a localized and quite extreme power differential.
As for why I voted for Trump, he is the lesser of two evils. After careful consideration of all the evidence of malfeasance on both sides of the aisle, Democrats came out worse. They were more racist, more misogynistic, more greedy, more warmongering, more freedom restricting, more censorial, more anti-scientific, and more hateful than their Republican counterparts.
Please note, this doesn’t mean that Republicans don’t also share these traits to a degree, it simply means that Democrats were *worse*. In particular, the complete lack of integrity on the part of the MSM, which would excuse any Democrat transgression, was a major issue. For all the hyperventilating you’ve been hearing since Trump was elected, Democrats have gotten a pass on the same, and worse. So, what you’ve woken up to is simply the truth about every government we’ve had, and I had a much greater fear of Democrats in power would get away with a complete lack of scrutiny from the fourth estate as they had for the previous 8 years.
I’ll give you one example — the right to self defense. As a citizen of the People’s Republik of Kalifornia, my right to self defense is constrained by the arbitrary decisions of politicians (to wit, I live in Los Angeles County, which has jurisdiction for approving CCW), who get to look at whether or not I’m a movie star, or a campaign contributor, and decide if I should enjoy my right to self defense. Trump got a replacement for Scalia (a hero of the right to self defense), Gorsuch, who had a similar philosophy of constitutional rights. Trump can tweet all night for the next four years, and still have done a better job of Hillary on the right to self defense when the SCOTUS strikes down unconstitutional limits on self defense.
Now, perhaps you have a completely different premise on whether or not self defense is important. Perhaps you see the individual right to self defense as archaic, or even deplorable. I can certainly understand that if you disagree with my premises, you may disagree with my conclusions. But please, understand this — rational, well-intentioned, genuine human beings can look at the same issue and come to diametrically opposed conclusions. It’s not because they’re stupid (you’re not), it’s not because they’re evil (you’re not), it’s because reasonable humans starting with different premises can honestly reach different conclusions.
Do, is Trump doing a “good job”? In some places, I think yes, in others, I think no. Is Trump doing a “better job” than Hillary would have? Absolutely. Could Sanders have made a better president than either of them? Quite possibly.