"[H]e came around grudgingly to supporting her, the advisers said. But he was also determined to make a strong case against Mr. Trump and, in doing so, champion Mrs. Clinton as the only chance to defeat him.... One person close to Mr. Sanders said that the senator and his wife, Jane, were 'putting on a good face' on Tuesday, but that they were disappointed that his campaign had not been more successful after he gave it so much of his energy and rallied millions of people around his ideas.... Still, Mr. Sanders uttered the words that Mrs. Clinton needed him to say — 'I am endorsing Hillary Clinton.'"
From the NYT report "Bernie Sanders Endorses Hillary Clinton, Hoping to Unify Democrats," by Amy Chozick, Patrick Healy, and Yamiche Alcindor. They include Trump's cutting reaction: “Bernie is now officially a part of a rigged system" for "endorsing one of the most pro-war, pro-Wall Street, and pro-offshoring candidates in the history of the Democratic Party."