It’s not a unique problem for the GOP. Republican candidates in Wisconsin lost earlier this year largely because of early and mail-in voting by Democrats, and Pennsylvania Republicans have tried to persuade their base to use vote-by-mail after statewide losses in 2022.

About 545,000 New Jerseyans had voted in advance of the legislative election, mostly by mail, according to The Associated Press. Of those, about 329,000 were registered Democrats and just 129,500 were registered Republicans.

In a low-turnout election with state lawmakers at the top of ballots, those margins can be decisive.

“It’s something that Republicans are going to have to get over, this idea that we shouldn’t vote by mail or that the races are stolen in the mail. It’s just not true,” said Chris Russell, a Republican strategist who worked on several New Jersey legislative campaigns and an independent expenditure group.

“There are certainly instances of voter fraud … It’s not a perfect system,” he added. “But the idea that there is widespread voter fraud being committed is inaccurate, and to the extent our people continue to believe that, we’re going to lose elections.”

New Jersey Democrats have spent years honing their vote-by-mail programs. In 2018 and 2019, they passed laws that automatically sent vote-by-mail ballots to everyone who signed up for one in the 2016, 2017 and 2018 elections. That led to thousands of disproportionately-Democratic voters who normally would only turn out for more high-profile elections getting ballots in the mail for off-year state legislative elections.

At the same time, then-president Trump, who remains the most influential figure in the party, sowed doubt about the integrity of vote-by-mail to the Republican base.

Republicans knew they had a problem. The Republican State Leadership Committee spent nearly $1 million to promote mail-in voting in New Jersey. The Republican State Committee also sought to encourage it. But they continued to be dwarfed by Democrats, who already maintain a nearly-million voter registered voter advantage.

“Coming into this year it was abundantly clear Democrats weren’t cannibalizing their own votes with vote–by-mail and early voting. They were doing a better job converting infrequent voters into every-year voters,” said Tom Szymanski, a former executive director of the state GOP who advised the Republican State Leadership Committee on its vote-by-mail program.

Szymanski said that more Republicans voted by mail in almost every targeted state legislative district than the last state-level election in 2021. “But obviously digging out of a crater-sized hole cannot be done in one cycle,” he said.

Republicans didn’t solely place the blame on vote-by-mail. Democrats relentlessly attacked Republicans on abortion following the U.S. Supreme Court’s repeal of Roe v. Wade last year, spending millions on ads suggesting they would curtail access to it if they won power and using 2020 Facebook comments by state Sen. Ed Durr (R-Gloucester) that women have the choice to “keep their legs closed” as an albatross for Republicans around the state.

Republicans countered by accusing Democrats of using the issue to change the subject and saying that their party would not overturn abortion in a state with some of the strongest protections for the procedure in the nation.

But state Senate Minority Leader Anthony Bucco acknowledged in an interview with The Star-Ledger editorial board that they might try to roll back some of the more “extreme” abortion laws and that millions for state funding for health clinics that provide abortions could be in jeopardy should his party take control.

“Abortion still resonates deeply. I think you saw that across the board. The Republicans said, at the minimum from Tony Bucco, that if they were to get majorities again they would defund Planned Parenthood and restrict abortion rights,” Gov. Phil Murphy said in an interview Wednesday. “Everybody knew, at least on our side, that it wasn’t changing the subject. I was the subject.”

Some Republican candidates were caught seemingly off-guard on the issue. In the 11th Legislative District, where both political parties spent the most money, unsuccessful Republican state Senate candidate Steve Dnistrian refused to take a position on abortion rights when asked in a TV interview. In the ultra-competitive 16th District, Republicans for a second time ran former U.S. Rep. Mike Pappas, who opposes abortion even in cases of rape and incest.

“Republicans who continue to put their heads in the sand on abortion are going to continue to pay a price for it. We need to understand the ground has shifted on that issue and meet voters where they are,” Russell, the strategist, said.

Republicans also based much of their campaigns on opposition to state sex education guidelines that had stirred opposition at raucous school board meetings; state lawsuits against school districts that adopted parental notification policies if students identified as a different gender than they were assigned at birth; and school library books with frank depictions of sex.

But while those issues may have excited the Republican base, they didn’t appear to get lower-propensity voters to the polls.

State Sen. Jon Bramnick, one of the few Republicans in New Jersey who proudly calls himself a moderate, said the problem isn’t vote-by-mail but the deterioration of the Republican brand thanks to Trump and inflammatory radio hosts like NJ-101.5’s Bill Spadea, a potential candidate for governor in 2025. Spadea did not respond to a request for comment.

Bramnick and Republicans made big gains in his hometown of Westfield — a formerly Republican town that went to Democrats in the Trump era — as well as nearby Summit because they had “good candidates” and voters “started to trust Republicans again.”

But it’s a different story elsewhere.

“The Republican brand is still really in bad shape, still suffering in New Jersey from Donald Trump with swing voters,” Bramnick said. “You’ve got this Bill Spadea on the radio. There are people listening to that who are not Republican and they say ‘Oh my god, this is the voice of Republicans?’”

He added: “You can’t say I don’t want to talk about Trump because he’s not running in New Jersey. Yes he is. He’s running right on your shoulders, buddy.”

Daniel Han contributed to this report.