Mike Bloomberg said Tuesday he would not run for the White House in an opinion piece in which he ripped President Trump as “a con” whose first term will be remembered as “four years of chaos, disruption and deceit.”

“I’ve never made any secret of my belief that Donald Trump is a threat to our country. At the 2016 Democratic National Convention, I said: ‘New Yorkers know a con when we see one,’” he said in a lengthy piece published on his eponymous news site.

“Last fall I spent more than $100 million supporting Democrats in the midterm elections. Republicans in Congress had failed — and are still failing — to fulfill their constitutional duty to hold the president accountable. Instead, they indulge his worst impulses and refuse to work with Democrats on the most urgent issues,” the three-term Gotham mayor continued.

Still, Bloomberg predicted he could have beaten Trump in a 2020 face-off.

“I know what it takes to run a winning campaign, and every day when I read the news, I grow more frustrated by the incompetence in the Oval Office,” he said.

“I know we can do better as a country. And I believe I would defeat Donald Trump in a general election. But I am clear-eyed about the difficulty of winning the Democratic nomination in such a crowded field.”

Trump mocked Bloomberg during a November Oval Office sitdown with The Post.

“I’d love to run against Little Michael. I would love to run against him. He’s been fighting me hard. He spent $100 million against me – that didn’t work,” he said, though Democrats easily recaptured control of the House.

Senate Majority Leader Chuck Schumer, however, said that Bloomberg would have been a formidable challenge to Trump.

“Mike Bloomberg was a great mayor and would have been a strong candidate,” Schumer said in a statement.

“I am certain his passion for making the country a better place will continue, albeit not as a candidate, particularly on issues like climate change, guns and curtailing the abuses of President Trump.”