Trump knows dick about governing. He's too egotistical to choose advisors that would cover the gaps in his knowledge, and his foreign policy experience is zero. His lack of preparation for this process is extreme, he speaks off the cuff constantly, and has nowhere near the credibility with other countries that he would need. He doesn't want the job, he just wants to prance around in the public eye for a while. He has no chance of winning, and the most he would accomplish is by splitting the conservative vote during the General election by running as a third-party candidate. Which would be good if it put Bernie Sanders in office, and probably useless if it puts Hillary in. That woman is bought and paid for.