Sen. Phil Boyle (R-Bay Shore) speaks in Albany during the...

Sen. Phil Boyle (R-Bay Shore) speaks in Albany during the New York State Senate Standing Committee on Insurance on Jan. 6, 2016. Credit: Hans Pennink

Call it the Pellegrino effect.

Democratic Assemb. Christine Pellegrino’s special election upset in a heavily GOP district in May has created angst for state Senate Republicans over the prospect of another low turnout special election next February or March against Democrats, energized by President Donald Trump.

Their concern centers on the Fourth District seat held by GOP State Sen. Phil Boyle of Bay Shore, who is running for the $194,243-a-year job of county sheriff. Boyle himself is embroiled in a Republican primary against Larry Zacarese, deputy chief of the Stony Brook University police.

Although no one is talking about it publicly, major and minor party sources say Senate and local party officials are weighing whether to have Boyle resign his Senate seat early if he wins the Sept. 12 primary.

Boyle would have to resign by Sept. 20 to have the special election for his seat occur on Election Day, Nov. 7, when it’s likely that more Republican voters will show up at the polls.

“If I’m a GOP leader, I’d rather do a general election, not a special,“ said Desmond Ryan, a veteran Albany lobbyist.

A special election is “very expensive because you have to identify your voters, target them and get them to turn out when you don’t normally vote,” Ryan said. “A general election is much easier because a much larger number shows up.”

Ryan noted that the Fourth District race is crucial to Senate Majority Leader John Flanagan (R-East Northport), who has a razor-thin margin with the help of dissident Democrats.

“It’s like he’s holding on to a greased rope that could slip away any day,” Ryan said. Flanagan did not return calls for comment.

Boyle’s exit, party sources say, could set off other domino-like moves.

They include Suffolk County Legis. Tom Cilmi (R-Bay Shore) moving from a re-election bid to a Senate race; Islip Town Councilwoman Trish Bergin-Weichbrodt seeking Cilmi’s legislative seat; and Assemb. Andrew Garbarino, son of the Islip GOP leader William Garbarino, or some other town Republican running for Bergin-Weichbrodt’s town board seat.

All those nominations would be done by a three-member committee to fill vacancies controlled by party leaders, precluding the possibility of primaries.

Boyle, who also has the Conservative and Independence Party lines for sheriff, would not comment on the possibility of leaving the Senate early, saying he was “totally focused” on the sheriff’s primary.

Zacarese said he’s aware of the maneuvering and “clearly it’s an issue.” He said Boyle should state publicly whether he intends to step down early.

Meanwhile, Suffolk Democratic Chairman Rich Schaffer, who remained neutral in the Pellegrino contest, said he intends to be more active the Fourth District race.

Schaffer, also Babylon Town supervisor, said the GOP wants to avoid a special election next year or keeping the seat vacant until the November 2018 elections, which would coincide with the midterm congressional elections with an expected heavy Democratic turnout.

Schaffer said among potential Democratic State Senate contenders are Assemb. Phil Ramos of Brentwood; lame-duck Suffolk Legis. Louis D’Amaro of North Babylon; Pellegrino; Philip Nolan, Suffolk Off Track Betting Corp. president and a former Islip supervisor; and former Suffolk County Executive Patrick Halpin.

“We will be prepared with a very strong progressive Long Island-centric candidate, who will represent our interests in the State Senate,” Schaffer said.