No, Trump is not too mentally unstable to be President
OK, folks, let's chill out about Donald Trump's mental stability and fitness to be President. That was already decided when he won the 2016 election, and (apart from his outbursts on Twitter) he has been a stable President with solid conservative policy and a good team around him.
Now, let's be clear. Trump is a very mercurial personality. He is a narcissist who has a need to be the center of attention at all times. He is way too thin-skinned, as we saw when he overreacted to mild criticism from Megyn Kelly and then was such a pathetic coward that he would not attend a debate she moderated. He is far too prone to post childish memes on Twitter, which is not just unpresidential but unprofessional. We would not tolerate this from the head of any major corporation.
But while being a childish, thin-skinned narcissist are bad character traits, they are not evidence of insanity or mental instability. Trump is not as bright as he claims to be but he is not stupid by any means. He leveraged his brand into being an international celebrity and won a Presidential race that he frankly should have had no hope of winning and would not have won had the Democrats not chosen a completely toxic nominee.
The reason people do not understand Trump is because we have not seen anything like this before - at least not at the level of the President. Trump has the tendency to cut a boastful pro wrestling heel promo. It is not that he even believes what he is saying, but he is not necessarily lying. The key is to take him seriously, but not to take every single word he says literally. Freaking out every single day about Trump venting frustration on Twitter or stroking his own ego in a speech is not good for your own mental health or your stomach lining. It is best to focus on policy and the way the administration is being managed.