UNITED NATIONS — With thousands of demonstrators protesting outside that he had stolen Iran’s election, President Mahmoud Ahmadinejad stoutly defended his legitimacy here on Wednesday, declaring in a speech that the Iranian “people entrusted me once more with a large majority” in a ballot he described as “glorious and fully democratic.”In a 35-minute address, Mr. Ahmadinejad leveled familiar attacks against the United States and delivered an oblique rant against Jews, saying it was unacceptable for…