Mike Bloomberg slammed President Trump – as well as his Democratic rivals – Saturday as he kicked off what he called “Day One” of his run for the White House.

“Unlike everyone else in this race, I think what’s important is beating Donald Trump,” he told about 45 supporters at a restaurant in San Antonio.

Protesters toting Trump 2020 and U.S. flags could be spotted through the eatery’s windows.

TV’s Judge Judy Sheindlin introduced Bloomberg with a dig at the left-wing Democrats running for the nomination.

“Those that are touting revolution in this country are wrong,” she said. “It’s the best country on earth … It should have the greatest president.”

In a 13-minute stump speech, Bloomberg touted his efforts to raise teacher salaries and cut carbon emissions during his three terms as New York’s mayor.

“America is not New York, I understand that,” he acknowledged. “It’s getting things done rather than partisan talking.”

But he stayed far away from his record on crime. He was forced to renounce his signature stop-and-frisk policing policy after being hammered by his fellow Dems.

Instead, he turned the spotlight back on Trump.

“When I’m in the Oval Office, no more tweeting,” he promised.

“Actually I can’t spell very well,” he admitted. “So that’s relatively easy to do.”

Bloomberg made four campaign stops in Texas on Saturday. Back in New York, his campaign opened a Harlem office with an event helmed by former Philadelphia Mayor Michael Nutter, Bloomberg’s campaign co-chair.

The billionaire has already burned through $200 million of his $50 billion fortune since declaring his candidacy seven weeks ago – and has said he will spend “whatever it takes” to prevent Trump’s re-election.

Bloomberg’s campaign has dropped $16 million on TV ads in Texas, second only to the $20.4 million he has shelled out in California, another state with a Super Tuesday primary on March 3.

Together, those two states will award a whopping 644 delegates – a third of the 1,990 needed to win the nomination.

“Texas is a much better target for Mike Bloomberg because Democratic primary voters there are more moderate than their counterparts in California,” Democratic strategist Brad Bannon told The Post. “When you hunt, you go where the ducks are.”

The national RealClearPolitics polling average has Bloomberg in fifth among the Dem candidates at 5.8% — a gain of just 3.3% since he announced his candidacy in November.