A Minnesota dad who ranted against President-elect Donald Trump online shot and killed his wife, ex-partner, and his two sons before turning the gun on himself, according to authorities.

The shooter, 46-year-old Anthony Nephew, had a “pattern of mental health issues,” Duluth Police Chief Mike Ceynowa said on Friday — one day after authorities found five people dead inside two homes in the city.

Authorities found Anthony Nephew’s ex-partner Erin Abramson, 47, and their son, Jacob Nephew, 15, dead from apparent gunshot wounds inside their home Thursday afternoon, police said.

After identifying Anthony Nephew as a suspect, police found his 45-year-old wife Kathryn Nephew, and their 7-year-old son Oliver Nephew dead from gunshot wounds inside their family home close by.

Anthony Nephew was also found dead inside the home from a self-inflicted gunshot wound, police said.

Before his rampage, Anthony Nephew had been sharing left-wing and anti-Trump posts on his Facebook account.

“My mental health and the world can no longer peacefully coexist, and a lot of the reason is religion,” Anthony Nephew wrote in July.

“I am terrified of religious zealots inflicting their misguided beliefs on me and my family. I have intrusive thoughts of being burned at the stake as a witch, or crucified on a burning cross.

“Having people actually believe that I or my child are Satan or, the anti-Christ or whatever their favorite color of boogie man they are afraid are this week.”

In another post, he accused Republicans of “making it harder for women to leave” abusive relationships.

“Gilead here we come,” he wrote, referencing “The Handmaid’s Tale,” a dystopian novel turned Hulu series in which women, who have been stripped of their rights, are forced to reproduce for the ruling class.

Anthony Nephew shared other political posts, including an image of former president Barack Obama, Trump, President Joe Biden and Vice President Kamala Harris. The word “hate” sits under Trump’s face, while the words “hope,” “heal” and “grow” correspond with the Democratic politicians.

“Not that anyone cares, but as an Independent voter, I would really like to see both the political parties in our country pick better candidates,” he wrote in July. “We can do better than a binary choice between fascism and not fascism.”

Anthony Nephew previously even issued a chilling warning about his mental health battles, writing in an op-ed in the local Duluth News Tribune in 2021, “For millions of Americans, a breakdown leads to suicide — or homicide before suicide.”

“Mental health in this country is stigmatized, ignored, or treated as a burden for the individual to bear alone, with little help and less understanding,” he wrote. 

“Americans deny they have mental health struggles. Because they have to, because they’re told to, or because they don’t realize their mind is broken.”

Police in Duluth, a city of nearly 90,000 residents about 135 miles north of Minneapolis, have not yet determined a motive in the shootings.

Police said there is no ongoing threat to the community. 

With Post wires.