(CN) — In just the fourth month of his candidacy, billionaire Democrat Mike Bloomberg dropped out of the Democratic presidential primary on the heels of disappointing Super Tuesday results.

Bloomberg served three terms as New York City mayor, from 2002 to 2013, and since has put millions into philanthropy, including the gun control advocacy group Everytown for Gun Safety.

With his late-entry announcement on Nov. 24, Bloomberg essentially bought his way to a strong start by spending over half a billion dollars on advertising over the next three months, according to his own news company. He dropped an average of $5.6 million on ads per day, the reporters found.

Ahead of Super Tuesday — in which voters in 14 states and one territory allocate one-third of the total delegates available to candidates — polls had the 78-year-old placing second or third in Texas, and third in North Carolina, Virginia and Massachusetts.

Those states ultimately went big for former Vice President Joe Biden, however, with Bloomberg winning only the territory of American Samoa. With just 44 delegates, Bloomberg found himself Wednesday morning in a very distant fourth place and endorsed Biden for the Democratic nomination.

“Three months ago, I entered the race for president to defeat Donald Trump,” Bloomberg said in a statement. “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.”

Bloomberg added: “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.”
Now the frontrunner for the Democratic nomination, Biden welcomed the mayor’s announcement. “This race is bigger than candidates and bigger than politics,” Biden wrote on Twitter. “It’s about defeating Donald Trump, and with your help, we’re gonna do it.”

Political consultant Alexandra Acker-Lyons said last month Bloomberg’s entry into the race was a good thing for Democrats overall.

“His ads targeting Trump have been, in some cases, the only negative ads against Trump anywhere,” she said. “He has a very strong digital presence, which I think is hugely important this cycle. He is talking about issues like gun safety and climate change that are important to Democratic voters.”

Having skipped the first four early primary contests in Iowa, New Hampshire, Nevada and South Carolina, Bloomberg’s name appeared on the ballot for the first time on Super Tuesday.

The media mogul spent $57 million of his estimated $60 billion fortune in Texas, stuffing Democrats’ mailboxes with mailers, sending text messages to their phones, and filling the radio and TV airwaves, especially Spanish-language stations, with his campaign ads. But he finished a distant third behind Biden and Sanders, with 15% of the votes and four delegates.

In the territory of American Samoa, Bloomberg won four of the five delegates with just under 50% of the vote. Hawaii Senator Tulsi Gabbard won the Pacific island’s remaining delegate with 29.3% of the territory’s vote.

During his brief run, Bloomberg faced widespread criticism both for his “stop-and-frisk” policy as New York mayor and for his comments about, and nondisclosure agreements with, women at his company who complained of sexual misconduct.

His first debate saw him hastily eviscerated over those NDAs by Massachusetts Senator Elizabeth Warren.

“I’d like to tell you about who we’re running against: a billionaire who calls women ‘fat broads’ and ‘horse-faced lesbians,’” Warren said at the Feb. 19 debate. “And, no, I’m not talking about Donald Trump. I’m talking about Mayor Bloomberg.”

A former law professor, Warren even drew up a release and covenant not to sue, saying Bloomberg could sign it to release the women from the agreements.

Bloomberg said two days later that any individual who wished to speak out should come forward.