John E. Sununu’s official launch of his 2026 campaign to return to the U.S. Senate was greeted with a surge of endorsements from fellow Republicans and a flurry of attacks from Democrats, both in New Hampshire and D.C.

Former Senator and Ambassador Scott Brown has been running since June, but that didn’t keep some of the biggest names in the New Hampshire GOP from throwing their support to Sununu.

“I’ve been endorsed by the New Hampshire Senate president (Sharon Carson), by former Sen. and Gov. Judd Gregg, by former Gov. Craig Benson, by Executive Councilors Janet Stevens, Joe Kenney, and John Stephen,” Sununu told radio host Jack Heath Wednesday morning just hours after his announcement video was released.

“I’ve been endorsed by Steve Stepanek, who ran Donald Trump’s campaign in New Hampshire in 2024. We have support from Republicans across the board from New Hampshire, and that just speaks to the strength of the race I’m going to run.”

And several of New Hampshire’s major GOP donors have already organized a fundraiser, Politico reports. Among them:  Phil Taub, Joe Faro, Al Letizio Jr., Nick Vailas and Kelly Cohen.

Sununu also got the backing of some key national Republicans, including U.S. Sen. Tim Scott (R-S.C.), the head of the National Republican Senatorial Committee (NRSC).

“John Sununu’s deep roots and passion for the Granite State make him built to win,” Scott posted on Twitter/X. “New Hampshire is ready for a proven leader who stands up for seniors, fights for economic and educational opportunity, and delivers real solutions to make life more affordable and prosperous.

“The NRSC is all-in for John E. Sununu.”

And the Senate Leadership Fund, a big-dollar player in campaigns, also gave Sununu a thumbs up.

“John E. Sununu is a respected leader and a trusted voice for New Hampshire whose candidacy instantly expands the Senate map and puts the Granite State in play for Republicans,” according to a statement.

And while the Cook Political Report is keeping New Hampshire in its “Leans Democrat” column, Nathan Gonzales with Inside Elections raised his rating of the race from “Lean Democrat” to “Tilt Democrat” in response to the Sununu news.

Democrats didn’t wait for Sununu to announce his candidacy to go on the attack, launching an anti-Sununu website weeks ago. When the news came on Wednesday, they were ready.

“New Hampshire doesn’t need another entitled Sununu trying to fail upward,” said Nico Delgado, spokesperson for the Democratic Party’s rapid reaction organization American Bridge 21st Century

“John E. Sununu was the poster boy for trying to gut Social Security. He supported repealing the Affordable Care Act, praised Paul Ryan’s plan to end Medicare, and opposed abortion rights at every turn. Then he got rich working for the same industries he was supposed to rein in.”

U.S. Rep. Chris Pappas (D-N.H.) responded to the news by releasing a fundraising appeal.

“Republicans just got their hand-picked candidate to jump into this race, and they’re going to spend whatever it takes to flip this Senate seat,” Pappas said in a video statement. “This race might have just changed, but my commitment to taking on tough fights for the people of New Hampshire hasn’t.”

Democrats are also working Trump into the race right out of the box, injecting the word “MAGA” into their messaging.

“The New Hampshire Republican primary has devolved into a messy slugfest, pitting a corporate sellout against a MAGA hardliner. And voters know better than to trust either one,” said the Democratic Senate Majority PAC in a statement.

And New Hampshire Democratic Party chair Ray Buckley posted this message on Twitter: “John Sununu thinks MAGA hasn’t gone far enough.”

There has not been a significant amount of polling in the race, but the few numbers that have been released show Pappas with a narrow lead over Sununu (47-44 percent) and a more significant advantage over Brown (49-39 percent).

The Brown campaign attributes that to the Sununu name, and even some supporters acknowledge there is likely some confusion about which Sununu — John E. or his brother, former Gov. Chris — is on the ballot.

Brown pointed the press to a statement he released earlier this week that reads in part, “Anyone who thinks that a ‘Never Trump,’ corporate lobbyist who hasn’t won an election in a quarter century will resonate with today’s GOP primary voters is living in a different universe.”

After Sununu’s announcement, he added another comment via Twitter/X.

“John E. has officially entered the race. I look forward to drawing clear distinctions between us and letting the people of New Hampshire — not Washington, D.C. — decide who’s best suited to take down Chris Pappas.”