By Andy Sullivan and Makini Brice
WASHINGTON (Reuters) -New Hampshire Republicans chose far-right candidate Don Bolduc to take on Democratic U.S. Senator Maggie Hassan in November's election, Edison Research projected on Wednesday, potentially complicating Republican chances of winning a Senate majority.
Bolduc, a retired U.S. Army brigadier general, has echoed Donald Trump's false claims about 2020 election fraud and questioned whether the FBI should be abolished following its August search of the Republican former president's Florida estate, where agents seized a cache of classified documents.
His more moderate rival, New Hampshire Senate President Chuck Morse, conceded defeat.
"It's been a long night & we've come up short," Morse said on Twitter, adding that he had called Bolduc to congratulate him.
Republican voters also selected Trump-aligned candidates to take on New Hampshire's two Democratic incumbent House of Representatives members, Edison projected.
"Nice! The 'Trumpiest' people ALL won in New Hampshire last night," Trump said on Truth Social, his social-media platform.
New Hampshire could play a key role in the Nov. 8 election that will determine control of Congress, as both Hassan and the state's two House Democrats are considered vulnerable by nonpartisan analysts.
Some election trackers said Tuesday's results would make it easier for the Democrats to hold on to their House seats.
Taking back either the Senate or the House would give Republicans the power to bring Democratic President Joe Biden's legislative agenda to a halt and launch potentially politically damaging probes.
But as in other states, some Republicans have worried that candidates who echo Trump's divisive style could hurt their chances.
The state's Republican governor, Chris Sununu, argued that Bolduc would not be as competitive in a general election as Morse. An outside Republican group also spent heavily on Morse's behalf in the closing days of the campaign.
But it was not enough to defeat Bolduc, who analysts say will have a harder time appealing to the independent voters who make New Hampshire a closely contested state.
"The race will still be tight, but his right-wing stance may shift just enough independents who lean Republican to shift to the Democrats," said Linda Fowler, a professor of government at Dartmouth College.
Aside from New Hampshire, Rhode Island and Delaware also held primaries on Tuesday on a night that concluded months of state nominating contests.
Top Senate Republican Mitch McConnell has put his party's chances of winning control of that chamber at "50-50," noting concerns about "candidate quality" without singling out any specific candidates.
Bolduc starts the race at a clear financial disadvantage, having raised only $579,000 as of Aug. 24, compared with $31 million for Hassan. The Senate Leadership Fund, a national group affiliated with McConnell, has said it plans to spend $23 million on attack ads to help the Republican nominee.
Nonpartisan analysts say the race will be tight, but Hassan holds the advantage.
New Hampshire is one of seven key battlegrounds along with Georgia, Pennsylvania, North Carolina, Wisconsin, Arizona and Nevada that analysts believe will determine control of the 100-seat Senate. The Senate is currently divided 50-50, with Democrats holding a majority thanks to Vice President Kamala Harris' tie-breaking vote.
In the 435-seat House, Republicans need to pick up only four seats to win control, and both of New Hampshire's seats are likely to be up for grabs in November.
In a district that covers the eastern half of New Hampshire, Republican voters selected Karoline Leavitt, a former Trump White House press office official who has parroted his false 2020 claims, to take on incumbent Democratic Representative Chris Pappas.
Sabato's Crystal Ball, a nonpartisan election tracker, said that race now moves from a toss-up to a slight Democratic advantage.
Another nonpartisan firm, the Cook Political Report, likewise moved the other House race to "Lean Democrat" after former Hillsborough County official Robert Burns defeated a more centrist candidate, Keene Mayor George Hansel, in the contest to face Democratic Representative Ann McLane Kuster.
In Rhode Island, state Treasurer Seth Magaziner won the Democratic primary for an open House seat, while centrist Republican Allan Fung ran unopposed in his primary.
(Reporting by Andy Sullivan; Additional reporting by Makini Brice and Doina Chiacu; Editing by Scott Malone, Cynthia Osterman, Mark Porter, Will Dunham and Jonathan Oatis)