The Donald has announced that he will not be a candidate for the Republican nomination for president. You can find the statement here on the BBC News website. I don't think too many people are surprised inasmuch as running would have crimped his style, financially and otherwise.
This is not the beginning of the end, but it may be in Churchill's words, near the end of the beginning, the beginning of the process of finding a nominee. Winston could certainly use our language well.