Republican Anthony Constantino holds a comfortable 10 point lead over his Democratic rival in the race to succeed retiring GOP Rep. Elise Stefanik in upstate New York, according to a new poll.

Constantino, a pro-President Trump businessman, leads dairy farmer Blake Gendebien 50% to 40%, with 10% unsure, in the election for New York’s 21st House District, the survey conducted by J.L. Partners claims.

When undecided voters are pressed on who they lean toward, Constantino’s lead jumps to 13 points, 53% to 40%, with 7% undecided.

Anthony Constantino delivers his victory speech after defeating Assemblyman Robert Smullen in the Republican Party Primary for the 21st Congressional District on June 23, 2026, in Mayfield, New York. Albany Times Union via Getty Images

The findings rebut a News Channel 13/ Survey USA poll released last week that claimed Gendebien was up by 4 points, 43% to 39%.

“Though Republicans face a tough race in the House this fall, one thing is clear: New York 21 is not one of those vulnerable districts,” said pollster James Johnson, co-founder of J.L. Partners.

More than half of likely voters — 53% — had a favorable view of Stefanik, including 40% who viewed the six-term congresswoman very favorably, according to the J.L. Partners poll.

The staunch Trump ally, who was first elected to rep the district in 2014, announced in December that she would not be running for another term, as she also ended her bid for governor.

Her term ends in January.

Incumbent Gov. Kathy Hochul, who will lead the Democratic ticket, is deeply unpopular in the district that borders Canada, with 67% disapproving her job performance, including 58% who strongly disapproved, the poll said.

GOP candidate for governor Bruce Blakeman is viewed more favorably, with 47% having a positive view, 25% negative and the rest unsure or having never heard of him.

“With high favorability for Stefanik, Constantino, and Blakeman, it is a district where the Republican candidate is running ahead by double digits,” Johnson said.

The poll of 500 voters from Aug. 15-17 has a margin of error of plus or minus 4.4 percentage points.

Constantino and Blake Gendebien are vying to fill Elise Stefanik’s upstate seat. Hans Pennink for the NY Post

J.L. Partners was one of the most accurate pollsters in 2024, predicting that Trump would win the popular vote, as well as the electoral college, in the presidential race against Kamala Harris.

Constantino, a pugilistic pro-Trumper who runs the Sticker Mule company — and famously put a huge “Vote for Trump” sign on the roof of his upstate factory — has stirred up controversy, and even made enemies on the political right.

New York State Conservative Party Chairman Gerard Kassar filed a defamation suit against Constantino, for claiming Kassar threatened to kill the candidate.

The case is active.

The Conservative Party backed Republican Assemblymember Robert Smullen, who lost to Constantino in the GOP primary, and the ballot line will be blank in the general election.

Gendebien, who co-owns Twin Mills Farms in Ogdensburg near New York’s border with Canada, also has made comments that have come back to bite him.

He once ridiculed his upstate constituents as too lazy and too boozed-up to work for him compared to migrants.

“Three Hispanic employees. They would need to be replaced by probably six local people,” the Democrat said in a 2013 interview.

“It’s hard to find one local person that doesn’t have domestic abuse problems, alcohol problems, wage garnishments,” he claimed. “They show up late. They drink too much. There is just no labor force out there.”