Ed note: The day after this story was published, Rep. O’Brien died of a heart attack in his Fishtown home. Flags flew at half-staff across the commonweath in his memory.

In politics, sometimes you rumble in the streets. Sometimes you just leave an angry voicemail.

State House candidate Patty-Pat Kozlowski took the latter option last week after onetime friend Pa. Rep. Mike O’Brien endorsed Kozlowski’s political opponent at a recent campaign event, while also making a veiled jab at her leaving the Democratic party.

Kozlowski, a former Democratic political aide and longtime neighborhood civic leader, is running on the Republican ticket against Democrat Joe Hohenstein to take the reins of the 177th Pa. House District, which covers part of the River Wards and lower Northeast Philly.

Retiring next year amid health issues, O’Brien appeared in his wheelchair at a recent campaign event for Hohenstein in Port Richmond’s Campbell Square. O’Brien didn’t denounce Kozlowski by name, but did speak of people who “suck the barrel dry” and then “turn Republican.”

After the event, Kozlowski left a followng voicemail at O’Brien’s district office.

“Hey, this is Patty-Pat Kozlowski,” she said. “This message is for State Representative Mike O’Brien…You fat bastard! Next time you’re dying in Northeastern Hospital and you call someone to feed you Breyers and Diet Coke, lose my number… Really?”

Speaking to Billy Penn, Kozlowski called her missive a “a loving message,” and added that she “hoped [O’Brien] laughed about it.” She also acknowledged that she was hurt by O’Brien’s public betrayal of an old pal due to party lines.

“Mike didn’t have to say anything, but he did. And I guess that says a lot about him,” Kozlowski said. “This is politics and I’m getting a baptism by fire in it.”

On Saturday, O’Brien shared an audio recording of the voicemail on Facebook. His post likened Kozlowski to a Mean Girls character and called her “completely unhinged.”

Old friends, new beef

Kozlowski and O’Brien both told a story of once-close friends and colleagues who worked together in the office of former State Rep. Marie Lederer, a Democrat.

When O’Brien was hospitalized with serious health issues in the early 2000s, Kozlowski visited him with his favorite indulgences at the time: Breyers ice cream, Diet Coke and Marlboro 72 cigarettes — the latter of which he’s since given up, he noted.

The two remained amicable over the years, they both acknowledged. Since 2007, O’Brien has been the state representative for Fishtown and Northern Liberties’ 175th District. Kozlowski went on to work for former City Councilwoman Joan Krajewski — another Democrat — and then later at the Department of Parks and Recreation. She announced her candidacy for the River Wards district adjacent to O’Brien’s earlier this year.

It is a uniquely competitive race. While Democratic voters hold a 2-to-1 registration edge in the district, Republican state Rep. John Taylor has maintained fiefdom in the 177th District for more than three decades. Taylor was long considered one of the last moderate GOP leaders statewide and a much-needed diplomat for the the city’s interests in GOP-dominated Harrisburg. Then he announced his retirement.

Kozlowski says she was approached by Democrats several times over the years about taking a swing at Taylor’s seat; she always declined. But when Taylor announced he was stepping down, Republican leaders tapped Kozlowski as a promising successor. She changed her affiliation from Democrat to Republican — something she’s done several times over the years, at one point registering as an Independent.

“I’m not far left, I’m not far right,” Kozlowski said. “I guess you would call me a rowhouse Republican.”

The state GOP has injected $150,000 into her campaign, according to a source. Hohenstein’s campaign has raised $100,000 since the primary election.

But come endorsement time, O’Brien said he never doubted where his allegiances would be.

Politics: ‘A blood sport’

The six-term Democratic lawmaker unflinchingly portrays Kozlowski as a party turncoat.

“I’m a Democrat and I support Democratic elected officials. When you see someone who sucks the barrel dry and then turns Republican, they have no honor. You can quote me on that,” O’Brien said, in a more pointed reiteration of his comment at the Hohenstein rally.

Kozlowski countered that she had refused to join public criticism of O’Brien after his own alleged “bait and switch” earlier this year: O’Brien waited until after the primary election to announce his retirement for health concerns. He was diagnosed with bladder cancer, he said. District Democrats then hand-picked O’Brien’s own chief of staff, Mary Isaacson, to replace him as the unchallenged Democratic nominee on the Nov. 6 ballot.

“His own party bashed him on that change, but I stayed quiet on that,” Kozlowski said. “I didn’t know Mike was pissed at me [for changing parties].”

O’Brien, who said he’s on the verge of major surgery, said Kozlowski’s reaction via the message on his answering message shows a temperament unfit for public office.

“Politics is a blood sport. When you run for office, you open yourself,” O’Brien said. “Very thin skin, Patty-Pat… This is not somebody who’s going to be able to take the slings and arrows of Harrisburg. In the 12 years I was there it continues to slide to the right, and the new class coming in is going to be even more conservative.”

Kozlowski would be the first lesbian lawmaker in the General Assembly — a fact she makes a point not to campaign on. (“I’m not playing the gay card,” she says.) She instead touts her record of constituent service across several state and city offices, as well as her vehement stance against opening a safe injection site in the opioid-plagued district.

As for the fallout with O’Brien, she says her upset has settled down.

“You know what? At the end of the day, I’m still Mike O’Brien’s friend,” she said. “It’s not about the party for me. It’s about the person.”