A construction worker, a fisherman and a woman walking by the United Nations were knifed to death in Manhattan in separate, random attacks on Monday by a blood-covered lunatic with a long rap sheet who should not have been loose on the streets.

Three lives lost. Three more reasons to rid this city of Manhattan District Attorney Alvin Bragg.

Pundits say Bragg — the soft-on crime lefty largely responsible for the mayhem on New York City’s streets — will likely coast to reelection next year.

That would disgrace New York City. But it’s not a fait accompli.

True, no Democrat has emerged yet to challenge Bragg in the upcoming June 25 primary. But data from the recent presidential election suggest defeating Bragg is possible.

If there’s a candidate. Now that the numbers show a sizable shift in Manhattan voting, it’s the duty of the city’s political decision-makers to back a candidate who will give the criminal-coddling DA a run for his money.

The same seismic shift in urban voting attitudes is occurring across the nation. Urban Democrats are fed up with the crime, mayhem, homeless encampments, drug use and squalor that progressive policies have wreaked on their cities.

On Nov. 5, voters in the bluest areas of California rebelled. They dethroned Oakland Mayor Sheng Thao, Alameda County DA Pamela Price, San Francisco Mayor London Breed and Los Angeles’ Soros-backed DA George Gascon. Blue California overall backed Proposition 36 to strengthen drug and shoplifting penalties.

Manhattan voters will have an opportunity to oust Bragg in less than a year. The shift in voter sentiment suggests it’s time to seize it.

Citywide election results were even more promising. Trump gained voters. But a far larger number of disaffected Democrats — that growing reservoir of persuadable purple voters — stayed home rather than vote for the progressive policies that have doomed their neighborhoods.

Citywide, 573,618 fewer New York City voters cast their ballots for Harris than for Biden in 2020. Trump gained 94,611, but most of the rest sat out the election. Again, the citywide drop in population had some impact, but even so, hundreds of thousands of Democratically inclined voters refused to follow the party leader’s leftward lurch.

That’s a sizable voting bloc, considering only half a million people total (578,877) turned out for the November 2023 municipal election to elect the entire City Council. These disaffected democrats have the numbers to decide the next New York City election.

Public Advocate Jumaane Williams blames the falloff in votes for Harris on “anti-Blackness and misogyny.”

Republican Party State Chairman Ed Cox said voters are fed up with the “ideological experiments” coming out of Washington, D.C. Democrat Mike Gianaris, deputy leader of the state Senate, said “Democrats who voted for Biden didn’t vote” this time around.

Journalist Ezra Klein pointed to “the rage I just hear from people in New York … the sense of disorder rising, not just crime, but homeless encampments, trash on the streets, people jumping turnstiles in subways, crazy people on the streets. You just talk to people and they’re mad about it.”

That anger isn’t going away now that the presidential election is over.

In Manhattan, disaffected Democrats are numerous enough to wage a formidable campaign against Bragg.

There’s no better cause. Bragg prosecutes Daniel Perry but allows deranged fiends — walking time bombs — with long rap sheets to go free, causing the rest of us to fear getting slashed, punched or shoved onto the tracks. Time to seize this opportunity to oust him.