In 2011, Trump began a run for President. In 2013 he went to Russia, where they no doubt
urged him to run again.
https://www.theguardian.com/world/2011/may/16/donald-trump-us-presidential-race
In a statement, he said: "After considerable deliberation and reflection, I have decided not to pursue the office of the presidency. This decision does not come easily or without regret, especially when my potential candidacy continues to be validated by ranking at the top of the Republican contenders in polls across the country."
Modesty is not a Trump characteristic and this is reflected in his statement. "I maintain the strong conviction that if I were to run, I would be able to win the primary and, ultimately, the general election."
He added: "I have spent the past several months unofficially campaigning and recognise that running for public office cannot be done half-heartedly. Ultimately, however, business is my greatest passion and I am not ready to leave the private sector."