AMSTERDAM — Anthony Constantino believes that New York Conservative Party Chairman Gerard Kassar attempted to kill one of his top political aides, further fallout from his contentious bid to be the next representative for the 21st Congressional District.

On Thursday, Constantino hosted a rally in the shadow of his Amsterdam factory — right underneath the “Vote for Trump” sign he put up on the century-old building that marked his first foray into the political arena. In an hourlong speech to a crowd of a few hundred local residents and fans of President Donald J. Trump, Constantino pilloried his political enemies, from the mayor and police chief of his home city to Kassar and the political leadership that oversaw the aborted NY-21 special election. Chief among his enemies, apparently, is the Conservative Party chairman.

Constantino, the CEO of custom printing company Sticker Mule, said that shortly after the 2024 election, when Trump nominated Rep. Elise M. Stefanik, R-Schuylerville, to be his United Nations ambassador and he had thrown his hat into the ring as a potential nominee to fill Stefanik’s seat, he got a threatening call.

“‘We intend to kill you,’ the caller said, ‘we will destroy you,’ he continued,” Constantino quoted from the podium. “Followed by, ‘it’s just business.’ The call came from a political power broker who was very upset about my involvement in New York politics.”

Constantino later identified the caller as Kassar, chair of the state Conservative Party, a downballot party that frequently works with the state Republican operation.

The Conservative Party acknowledged that Kassar had made the call. Party spokesperson William O’Reilly shared a one-sentence response when reached.

“We stand by our decision not to support him (Constantino),” O’Reilly said, adding that Constantino should share the full, unedited audio of the call.

Throughout his speech, Constantino derided Kassar as a “New York City fat cat,” who relied on the donations of Conservative Party members to live. He repeatedly derided Kassar for his weight and appearance.

“Fat Jerry, sorry, you’re not supposed to say that, but you can make fun of people for their weight if they’re fat because they eat with other people’s money,” Constantino said. “If he wasn’t soaking in all the donations he’d probably look a little different.”

Constantino played a short clip of the call, which he recorded. In it, Kassar tries to discourage Constantino from running in the special election in NY-21, telling him in no uncertain terms that he wasn’t welcome in the race.

“We know what the Trump administration is looking for in Congress, there’s plenty of Congress members that we’ve elected over the years,” Kassar said. “You tell us what you think about how we could be smarter, we’ll just tell you to go f*** yourself.”

Kassar, in the call, questioned if Constantino would be able to flip voters or convince elected Congress members to take positions aligned with him. They added that Constantino, who was formerly a registered Democrat, didn’t need to work to flip voters in NY-21, which has been a solid Republican seat.

“We don’t anticipate losing this district,” Kassar said. “There’s three announced Republican candidates who are state legislators, there’s Joe Pinion that’s also announced.”

He listed Sen. Daniel G. Stec and Assemblymen Robert Smullen and Chris Tague as interested Republicans in the district who were stronger candidates than Constantino, and said that Stefanik, Trump and House Speaker Mike Johnson would also lend their input on the nominee. In New York special elections, the party chairs in the district with the congressional vacancy choose the party’s nominee, giving the party’s more senior members more than typical influence over the selection process.

The clip Constantino showed of the call appeared to cut off after Kassar laid out the senior electeds who had their eyes on the election. Constantino said that he hasn’t made public the entire call, but would release the full audio on his social media. The call audio wasn’t available by press time on Thursday night.

Constantino had previously floated potentially running again in the general election next year if he wasn’t the pick this year, or mounting an independent bid in the special election.

“Telling us that you’re going to run in November, it’s just a bigger reason why we have to kill you,” Kassar said in the call.

“In November?” Constantino replied.

“If you decide to run, if you get knocked out of the special and you tell us you’re gonna run in November, we’re going to do everything in our power to make sure you’re destroyed before you get to November,” Kassar said. “It’s just businesses, that’s how we all do it.”

The clip ended there.

Constantino said he ignored the incident until recently, when his press aide, Paul Antonelli, called him to report that his car’s brake line had been cut. Constantino said Antonelli had taken the car to a local auto body shop and the owner informed him that the lines had been cut. He said there was no evidence of rusting or other damage to explain the break.

In his own speech Thursday, Antonelli said he was grateful to Constantino for defending him. The former candidate has secured private security to protect himself and his campaign. A team of black-suited men with earpieces milled around at Thursday’s event.

Antonelli said he didn’t realize his brakes were out until the pedal stopped working while he was on the Thruway, Interstate 90, going about 65 mph. He said he pulled into the New Baltimore rest stop after traveling for a few miles.

The New Baltimore rest stop is south of Albany on the Thruway, about 50 miles from Antonelli’s registered address in Amsterdam, where he said the brake line was cut in the driveway of his home in the early morning of April 9. He said the car was towed to C.W. Albright and Sons, which he identified as “Albright’s Garage,” about 17 miles from the rest stop. The garage was closed for the day before Constantino and Antonelli spoke on Thursday, and the owner could not be reached to confirm what they alleged.

Constantino tied the timing of the break to a legal battle he’s been fighting against former NY-21 special election candidate Elizabeth “Liz” Joy. Joy had been supported by Kassar, alongside Stec and Tague, which angered Constantino. In April, when Trump rescinded Stefanik’s U.N. ambassador nomination, Constantino and Antonelli took out a full-page ad in the Schenectady newspaper listing “winners and losers” of the aborted special election. Among the losers were Joy and Kassar. Joy subsequently sued both Constantino and Antonelli for defamation.

“It seems highly likely that Paul’s brake lines being cut later was related to my disruption of New York politics, the New York political establishment. Paul related his concerns about Chairman Kassar, Liz Joy, and others to the Amsterdam police, who sat on the case for a week,” Constantino said.

Constantino called for the resignation of Amsterdam Mayor Michael Cinquanti and the police chief over the issue. He has also been fighting the city for months over his “Vote for Trump” sign and subsequent plans to build a Trump memorial park in the shadow of the sign.

Amsterdam Police Chief Joseph Spencer could not be reached for comment on Thursday afternoon.

Constantino made clear on Thursday evening that he will continue to be an active player in New York politics. He said he will spend “millions” of his own money to elect Republican and Conservative candidates across the state, working with Republicans for National Renewal, an organization that works to elect people with “traditional conservative values with nationalist and populist ideas.”

Constantino also didn’t rule out a future congressional run.

“It’s a fluid situation, so we’ll see what happens,” he said. “I just want to be helpful.”