With 2022 being hailed as a “red wave” year and Republicans holding a slight but consistent edge in generic ballot polling, many are wondering: Why is the GOP having so much trouble winning the Senate?

The answer, it appears, is that voters want Republicans but they don’t want the Republicans on their ballots.

While Republicans nationally maintain a slight edge over Democrats, this year’s U.S. Senate election map, combined with a number of underperforming candidates, appears to be aligning to deliver another two years of an even split in upper chamber.

According to Real Clear Politics, Republicans maintain a lead of 1.9 percentage points in the running average of the generic ballot polling. FiveThirtyEight reports a 0.9-point lead for the GOP in its  generic ballot average.

Simultaneously, FiveThirtyEight predicts the Senate will remain a 50-50 split in 2023. Decision Desk HQ predicts the same, even giving Democrats a slight edge.

With President Biden’s approval rating hovering somewhere in the mid-30s and most voters preferring a generic Republican, the story of how the GOP got here is one of President Trump’s continued influence over the party, at least according to some.

An associate editor at Sabato’s Crystal Ball, John Coleman, argues that Mr. Trump has helped propel a slate of weak candidates to the Republican nominations. 

“You have these candidates like [Mehmet] Oz and J.D. Vance and maybe even [Eric] Greitens in Missouri — these Trump-endorsed candidates are getting by with slim pluralities in primaries and struggling to build a coalition in the general election,” Mr. Coleman tells the Sun.

In the Pennsylvania GOP primary, Dr. Oz defeated Dave McCormick and Kathy Barnett by less than 1,000 votes, carrying only 31.2 percent of the vote.

Now, Dr. Oz is trailing Pennsylvania’s lieutenant governor, John Fetterman by at least four points in the general election polling, with some putting Mr. Fetterman as much as 10 points ahead.

In Ohio, Mr. Vance won the Republican primary with only 32.2 percent of the vote. Now he is trailing Representative Tim Ryan by 1.7 points, according to an average of polling.

In the Peachtree State, a former professional running back carrying an endorsement from Mr. Trump, Herschel Walker, sprinted to victory in the primary with an actual majority. Now, Mr. Walker has fallen behind his Democratic opponent, Senator Warnock.

Beyond the Senate, political strategists in the state have expressed  fears that a state senator, Burt Jones, a lieutenant governor candidate who received Mr. Trump’s endorsement, might sink the entire Republican ticket.

Mr. Coleman argues that Dr. Oz and Mr. Vance are weak candidates and says he expects Mr. Vance to “run a few points behind the rest of the Republican ticket.”  

 He cites Dr. Oz’s recent relocation to Pennsylvania from New Jersey as a liability that may make voters question his authenticity, while arguing that “if there’s anything John Fetterman has in spades it’s authenticity.”

A professor of political science at the University of Georgia, Charles Bullock, reports that the word on the ground in Georgia is that Mr. Walker’s Senate campaign will “self-implode.”

There is concern among some Republicans that Mr. Trump might put his weight on the scales to propel weak candidates to the nomination in other states as well, even if the races there may not be as close.

In Missouri, Mr. Trump’s apparent favorite for the Senate seat, Governor Greitens, is predicted to drastically underperform other Republicans in the state if he wins the nomination in August.

In Arizona, Blake Masters received Mr. Trump’s endorsement in the Republican primary and is now the clear frontrunner for the GOP nomination. However, Mr. Masters is also expected to underperform other Republicans in the general election, though less drastically than Mr. Greitens.

A senior data scientist at Decision Desk HQ, Liberty Vittert, observed that “Trump endorsees squeak by in the primary to struggle in the general.”

“Old-school Republicans who get the Trump endorsement fare better than the Trump-type candidates,” she tells the Sun. “It raises the question of whether the Trump endorsement really matters in the general election.”

A professor of political science at Hamilton College, Philip Klinkner, argues that the Senate map this election cycle is “pretty good for Democrats” but also that Republicans have hurt their chances with their nominees.

“I wouldn’t say that Trump is a drag on the Republicans at this point, but I will say that Trump has saddled the Republicans with some pretty weak candidates,” Mr. Klinkner tells the Sun.

He doesn’t rule out the idea that Republicans could still take control of the Senate, citing significant headwinds for Democrats trying to maintain an even split in the upper chamber.

“In general when the economy is bad, people blame the incumbents,” he said. “It sure didn’t help Jimmy Carter in 1980.”

Mr. Coleman agrees, but also argues that Mr. Trump is one of the most significant forces that may keep the GOP from wresting control of the Senate from Democrats.

“Mitch McConnell and the RNC ran an effective machine in 2014 and they’re not able to do that this year because if Trump is off doing his own thing that may interfere with their plans,” he said.

A political scientist at Rockhurst University, Thomas Ringenberg, argues a similar point, saying: “Trump can be a kingmaker in Republican primaries; those candidates don’t always go well in the suburbs.”

“If Trump wins, the thing they’re going to need is energy,” he said. “The one thing I’m waiting for is whether Trump announces a tour in all of these Senate states ahead of November.”