Michael Bloomberg confirmed Sunday that he is running for president, joining the crowded field of Democrats seeking to take on his fellow New York billionaire, President Donald Trump. His 11th-hour entry highlights the fluid nature of the Democratic contest just three months before the first primary. “I’m running for president to defeat Donald Trump and rebuild America,” Bloomberg, 77, said on his website as a $30 million Bloomberg ad campaign hit US airwaves. The announcement ended weeks of speculation that the former New York mayor was preparing for a run at the White House. He had prepared the groundwork for a possible bid for the Democratic nomination in recent weeks by registering as a candidate in primary voting states and filing paperwork with the Federal Election Commission.