A senior adviser to former New York Mayor Mike Bloomberg's now-defunct presidential campaign slammed President Trump Wednesday after the commander-in-chief trashed his fellow New Yorker on Twitter.

Timothy O'Brien, the campaign's senior adviser and the executive editor of Bloomberg Opinion, said Wednesday on "Bill Hemmer Reports" that he would have to "send the president a box of Pampers because what he really should be doing is focusing on the business of the country."

Trump predicted that Bloomberg will fire O'Brien, along with "all of the fools and truly dumb people who got him into" the Democratic presidential campaign.

"This has been the worst, and most embarrassing experience of his life...and now on to Sleepy Joe!" Trump crowed, adding that Bloomberg "didn't have what it takes" to win the presidency.

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O'Brien said he and the former Bloomberg team will continue to focus on issues in the presidential election and do what they can to help former Vice President Joe Biden win the White House.

"There’s the coronavirus that has people on edge, the stock market has been whipsawed. People have been concerned about the president’s competence for a long time," O'Brien told host Bill Hemmer. "I’m amazed that [Trump] can’t focus on what matters to the American people and he has to constantly personalize these sideshow issues,"

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When asked about Bloomberg's unprecedented personal expenditures related to his campaign, O'Brien said he never believed anyone could "buy" the presidency.

"As I said from the beginning, you can buy exposure, you can't buy an election. If you could buy an election, some of the candidates that came in with money and dropped out and never polled close to Mike Bloomberg would have been more formidable," he said, adding that the 78-year-old mogul's business success, mayorship and philanthropy prove that assertion.