Shortly after Joe Biden launched his 2020 presidential campaign bid on Thursday, a spokeswoman for his former boss, Barack Obama, said adding Biden to the ticket is "one of the best decisions" the former president ever made.

But Obama didn't offer a formal endorsement of his vice president in a statement issued by spokeswoman Katie Hill.

“President Obama has long said that selecting Joe Biden as his running mate in 2008 was one of the best decisions he ever made. He relied on the Vice President’s knowledge, insight, and judgment throughout both campaigns and the entire presidency. The two forged a special bond over the last 10 years and remain close today," the statement said.

Biden later told reporters at an Amtrak station in Wilmington, Delaware, that he'd asked Obama not to issue an endorsement.

"I asked President Obama not to endorse," he said. "Whoever wins this nomination should win it on their own merits."

Obama doesn't appear to have made any endorsement — at least publicly — in the 2020 race, which now includes 20 Democrats with Biden as a front-runner.

Biden is in his third quest for the White House, having ran in 1988 and 2008, before becoming vice president. Even before his announcement, he consistently led polls as a top Democrat to challenge President Donald Trump.

Obama endorsed his former Secretary of State Hillary Clinton in the 2016 campaign and stumped for Democrats in the 2018 midterm elections.

Biden, however, did pick up two endorsements on Thursday — from Democratic Sens. Chris Coons of Delaware and Bob Casey of Pennsylvania. Sen. Doug Jones, the Alabama Democrat, also pledged his support for Biden.

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The Republican National Committee immediately bashed Biden as "Crazy Joe" on Thursday, attacking his record while pointing out that Obama hasn't yet offered an endorsement.

“Joe Biden has been running for president and losing since the ‘80s. 2020 won’t be any different," said RNC communications director Michael Ahrens in a statement. "Biden’s fingerprints are all over foreign policy blunders and the weakest economic recovery since World War II. We don’t need eight more years of Biden. Just ask President Obama, who isn’t even endorsing his right-hand man.”

Biden, who hinged his campaign launch video on the violent 2017 clashes in Charlottesville, Virginia, was lauded by the city's former mayor, Mike Signer. In the video, Biden criticized Trump for his remarks in the aftermath of the clashes between white nationalists and counter-protesters. Trump had said there were fine people on "both sides."

"As the Jewish mayor of Charlottesville serving when @realDonaldTrump made his contemptible remarks giving safe harbor to neo-Nazis, I'm grateful to @JoeBidenf or centering his campaign on our Thomas Jefferson's 'idea of America': dignity for all," Signer said in a tweet.

Here's how others responded to Biden's announcement: