A Donald Trump supporter walked out of his Staten Island home early Sunday to find his giant sign dedicated to the Republican presidential candidate in flames on his front lawn.

Angry homeowner Sam Pirozzolo blamed the blaze on liberal haters of Trump’s inflammatory rhetoric.

“It’s a shame this generation that is around now, these kids, feel it’s fine to block my First Amendment speech — including almost setting my house on fire. To them, that makes sense,” Pirozzolo griped to The Post.

The NYPD said it is investigating the fire as an arson. Pirozzolo said an FDNY fire marshal told him the sign apparently was doused with gasoline before being ignited.

But Pirozzolo, 52, was left fuming after cops visited his home Sunday afternoon and told him the incident didn’t meet the official criteria to be considered a hate crime.

Under New York’s Penal Law, an offense can be prosecuted as a hate crime only if it targets a victim’s “race, color, national origin, ancestry, gender, religion, religious practice, age, disability or sexual orientation.”

“If this was about my religion or if I was gay, this would be a hate crime,” he said. “That someone can walk up, set a fire, burn my property and put my family in danger — it’s crazy not to make this a hate crime.”

A neighbor said the incident revealed a disturbing double standard in the treatment of liberals and conservatives.

“No one cares if you mess with a person wearing a Trump hat or shirt. Or burn a Trump sign,” said the neighbor, who declined to give his name.

“They let liberals do what they want. You think cops are looking for who did this?”

Neighbors leaving for vacation alerted Pirozzolo to the fire shortly after 1 a.m.

Pirozzolo, an optician, said he had installed the 12-by-8-foot “T” with a patriotic flag motif about two weeks ago. He noted that its destruction followed the disappearance of two smaller pro-Trump signs from his lawn Wednesday.

Pirozzolo commissioned the “T” from conservative Staten Island artist Scott Lobaido, who visited the crime scene and reacted in Trump-like fashion.

“I’m gonna build it bigger and better than before. It’s going to be yuuuge,” Lobaido said.

The sign was made out of a 1½-inch-thick foam panel, and the only parts that remained legible after the fire were a single white star on the left arm and two red and white stripes near the base.

“Instead of making a big sign that said ‘Trump,’ he made a big ‘T’ so we could support our candidate and prevent stuff like this,” Pirozzolo said.

City Councilman Joe Borelli (R-Staten Island), a co-chairman of Trump’s New York campaign, called the burning of Pirozzolo’s “T” “a clear line that’s being crossed.”

“It’s reminiscent of cross-burnings, and the message is one of intimidation,” Borelli said.

Borelli said a Trump sign was also stolen recently from outside his home in the Annadale section.

The billionaire businessman is scheduled to deliver a major speech Monday on the economy in Detroit, which in 2013 became the nation’s largest city to declare itself bankrupt.

Meanwhile, Trump took to Twitter on Sunday morning to bash outgoing Baltimore Mayor Stephanie Rawlings-Blake after her appearance on CNN’s “State of the Union” in support of Democratic rival Hillary Clinton, whom Trump calls “Crooked.”

“I see where Mayor Stephanie Rawlings-Blake of Baltimore is pushing Crooked hard. Look at the job she has done in Baltimore. She is a joke!” Trump tweeted.

Rowlings-Blake responded: “Girl bye, if he can’t take criticism from ‘a joke’, what’s he gonna do when somebody real comes for him? #notready”

Additional reporting by Daniel Prendergast and Marisa Schultz