Former New York City mayor Mike Bloomberg, a centrist billionaire who launched a White House bid after years of flirting with a run, and pledged to use his vast resources to unite Democrats and moderate Republicans against President Donald Trump has suspended his campaign and is endorsing former Vice President Joe Biden.

His campaign was shaken by Biden’s resurgence and overwhelming victory in the South Carolina primary, which reignited his bid and led other moderate candidates to drop out of the race end endorse him in an effort to consolidate the primary vote and prevent Vermont Sen. Bernie Sanders from clinching the party’s nomination. By Super Tuesday, it was clear that Bloomberg's efforts to target the 15 contests in play in lieu of traditional campaigning methods of hitting the early voting states simply did not pay off in terms of netting the bulk of pledged delegates or the popular vote.

“Three months ago, I entered the race for President to defeat Donald Trump. Today, I am leaving the race for the same reason: to defeat Donald Trump – because it is clear to me that staying in would make achieving that goal more difficult," he wrote in a letter to supporters adding “I’ve always believed that defeating Donald Trump starts with uniting behind the candidate with the best shot to do it. After yesterday’s vote, it is clear that candidate is my friend and a great American, Joe Biden."

Despite ruling out a White House run last spring, he reversed course in the fall and entered the race just before Thanksgiving, offering himself as a pragmatic problem solver with unlimited resources who could appeal to the middle of the country alienated by Trump and leading progressives, at a moment when former vice president Joe Biden faced questions about the strength of his campaign.

Bloomberg’s campaign surged after Biden’s disastrous fourth-place finish in the Iowa caucuses, impressing voters and Democratic officials with the size and scale of his operation despite skipping the first four early primary contests, and seizing on concerns that Sanders’ nomination could endanger down-ballot Democrats across the country this fall.

"Defeating Trump – and rebuilding America – is the most urgent and important fight of our lives. And I’m going all in,” Bloomberg said on his website at the time.