Taunton City Councilor Kelly Dooner, a Republican, declared victory Tuesday night over Raynham Selectman Joe Pacheco for a Massachusetts Senate seat that has long been held by Democrats but shifted purple after the 2021 redistricting process.

Dooner is set to expand the number of Republicans in the Senate, where conservatives have a super-minority caucus. The projected win also hands a boost to the Massachusetts Republican Party, which for months has been touting its ability to find winning candidates for local races.

A campaign spokesperson for Dooner told the Herald she declared victory just after midnight.

Results from the Associated Press last updated just after midnight showed Dooner leading with 14,998 votes compared to Pacheco’s 11,950. More than 28% of precincts were reporting at the time.

In a statement to the Herald shortly after midnight, Pacheco, who has no relation to outgoing Sen. Marc Pacheco of Taunton, said Rehoboth had not yet returned its results and “we’re taking the night and we’ll see where we are at tomorrow.”

“Every vote deserves to be counted,” he said

MassGOP Chair Amy Carnevale said immigration was a top issue in the race that likely convinced voters to back Dooner.

“Taunton has been hit hard by the immigration crisis,” Carnevale told the Herald. “A number of their hotels have been home to the so-called new residents under the Healey administration. And so I think that the potential flip there in that state Senate seat is really a reflection of the unchecked immigration policies on Beacon Hill.”

The race for the Senate seat, which stretches from Seekonk to Marion, heated up earlier this year after Marc Pacheco announced he would not seek reelection following 31 years in the Senate.

Marc Pacheco is the Senate’s longest-serving member and is known for his work on climate change, the service privatization law named after him, and lengthy floor speeches. His decision in February to forgo another term was part of a trend of veteran lawmakers bowing out of the Legislature.

In a social media post at the time, he said his departure from Beacon Hill did not close the door on other public service.

“While I am proud of all the work we have accomplished, much still needs to be done,” he said. “I look forward to working with my colleagues and everyone who is interested in making Massachusetts a better place to live; and while I am unsure what the future will bring, the door is always open for new and exciting opportunities.”

Joe Pacheco, who has won election to the Raynham Selectboard six times, has focused his campaign in part on the Steward Health Care bankruptcy, which threw into limbo the fate of Morton Hospital in Taunton. The facility has since been acquired by Providence-based Lifespan Health System.

He has also touted the endorsement of every public safety union in the state as well as the backing of U.S. Sen. Ed Markey, U.S. Rep. Bill Keating of Bourne, and Gov. Maura Healey, a Democrat who has lent her political clout to local races across Massachusetts.

Dooner was the youngest woman elected to the Taunton City Council in 2021 and moved to the city just over a decade ago after growing up in Randolph. She has focused on the high cost of running shelters housing local and migrant families and the state’s right-to-shelter law.

Gov. Maura Healey’s administration said it expects to spend more than $1 billion in each of the next several fiscal years on the emergency shelter system housing migrants and local families.

Former Gov. Charlie Baker, a Republican, endorsed Dooner last month, arguing she “has the vision, the energy, and the experience to make a positive difference.”

Both candidates have each raised and spent more than $100,000 this year, according to state campaign finance filings last updated Oct. 31.