New Hampshire’s Republican U.S. Senate candidates are prepping for their first televised debate Wednesday night, in a race that could help determine the balance of power on Capitol Hill and is dividing the Trump camp.

In what may be a boon to the incumbent senator, Maggie Hassan, no GOP candidate has yet emerged as the presumptive nominee with only three weeks until primary day. Considered one of the most vulnerable Democrats in the Senate, Ms. Hassan has an approval rating of 42 percent, and 39 percent of registered Granite State voters think she “deserves re-election,” according to an August 11 St. Anselm College poll. Yet the Cook Political Report now rates the seat as “lean D.”

The Supreme Court’s Dobbs ruling has increased Democrat voter enthusiasm in New Hampshire, according to polling, and expectations of a red wave nationwide are being readjusted. The Senate minority leader, Mitch McConnell, recently speculated that “there’s probably a greater likelihood the House flips than the Senate,” citing “candidate quality” as the biggest factor. 

His characterization could apply to New Hampshire.

In the Republican Senate primary, a retired brigadier general, Don Bolduc, has been “the clear front-runner all along,” the director of the New Hampshire Institute of Politics, Neil Levesque, tells the Sun, though he says the general is “thought of by people in campaign circles as not a threat because he doesn’t raise a lot of money and he’s said some pretty controversial things.”

A self-styled “outsider candidate” who aligns himself with President Trump’s agenda and disputes the 2020 election results, General Bolduc commands the lead with 32 percent support among registered GOP voters, according to the most recent poll from St. Anselm College. 

Yet he has had some missteps and ruffled feathers in the political establishment, such as calling New Hampshire’s governor, Chris Sununu, a “communist sympathizer” during a radio interview, calling for CIA operatives on the ground in Ukraine, and saying in a debate that he favors a repeal of the 17^th Amendment, which allows for the direct election of U.S. senators.

The president of New Hampshire’s senate, Chuck Morse, the so-called establishment candidate, comes in a distant second in recent polling, with 16 percent support. The former Londonderry town manager, Kevin Smith, a cryptocurrency millionaire, Bruce Fenton, and businessman Vikram Mansharamani register in the low single digits.

The race, though, is still wide open, with 39 percent of primary voters saying they are undecided.

Mr. Levesque says the upcoming debates and the possibility of endorsements from New Hampshire’s popular, moderate governor or from Mr. Trump are the only “change points” left in the weeks until primary day that could upend the race.

In a nationwide primary season defined by competitive GOP races between MAGA Republicans and establishment conservatives — often framed as a test of Mr. Trump’s enduring popularity — the former president’s endorsements have helped propel several struggling candidates over the finish line. He is expected to weigh in on the New Hampshire primary, according to his former campaign manager, Corey Lewandowski, but the Trump-versus-establishment-conservative rubric isn’t playing out as clearly in the Granite State.

A New Hampshire resident, Mr. Lewandowski is pushing hard for Mr. Trump to endorse “anyone but Bolduc,” he tells the Sun — though the general would be an obvious choice. In press interviews and an op-ed  in the Daily Caller, Mr. Lewandowski is vocally opposing the general, whom he calls a “war monger” and “the exact antithesis” of someone who follows Mr. Trump’s America First agenda.

A former Trump adviser, Steve Bannon, is taking the opposite position. During a recent episode of his “Real America’s Voice” show, Mr. Bannon endorsed General Bolduc and dubbed the race the “Wyoming of New England.”

Mr. Morse is the obvious Liz Cheney comparison.

Governor Sununu suggested recently on New Hampshire Today radio that he “may endorse someone.” That person will likely be Mr. Morse, with whom Mr. Sununu has worked closely at the state house for years.

On General Bolduc, the governor doesn’t mince words: “I don’t take him as a serious candidate. I don’t think most people do.” He called the general a “conspiracy theorist type.”

Mr. Morse is unexciting, a policy wonk by comparison, but his campaign is embracing the label. “He’s a work horse, not a show horse,” a Morse campaign adviser, David Carney, tells the Sun.

Expect some fisticuffs at the debate Wednesday night. The libertarian Republican candidate, Bruce Fenton, will likely attack Mr. Morse on his record, particularly regarding Covid restrictions. Mr. Smith, attempting to revive his campaign after a lackluster performance in recent polls, will hit General Bolduc hard on some of his extreme comments. The general will attack Mr. Morse, his clearest threat.  

All the candidates will attack Ms. Hassan for “reckless spending” in Washington, for her vote in favor of the Inflation Reduction Act and the hiring of 87,000 new IRS agents, and for her support of abortion without restrictions. Crime, border security and immigration, and “parental rights” in education will also feature prominently.  

“With each debate, the Republican Senate candidates get nastier and their attacks on each other get more brutal,” the New Hampshire Democratic Party chairman, Ray Buckley, tells the Sun. “I expect we’ll see even more radical positions from the candidates at the Newsmax debate.”

New Hampshire holds its election on September 13, the last date in the national primary schedule. The GOP nominee will then need to pivot quickly to appeal to general election voters. 

The candidate whom Mr. Trump will endorse is anyone’s guess. Expect an audition tonight.