Donald Trump often states that he puts America in the first position of importance.
Trump is a liar. What he values most is his pride. If you criticize him, he will try to hurt you in any possible way. "If people hit me, I will certainly hit back. That will never change," Trump declared (according to a report by the "New York Times").
Unlike the regular folks, Trump has both extreme wealth and the extreme power that such wealth entails. They ensure that Trump is safe from any harm caused by even the most severe criticism. There is no reason whatsoever for him to "hit back" at people who have much smaller socioeconomic stature than he has.
Yet, Trump continues to engage in petty fights with his critics even though such fights convince an increasing number of voters to vote against him. In order to satiate his pride (in himself), Trump is willing to lose in the presidential election in order to "win" these petty fights. For him, his pride is more important than fixing the numerous problems (that affect regular folks) as president of the United States.
Trump has betrayed us -- the regular folks. His claim about wanting to help us is a lie
For Trump, America is not first. His pride is first.