PHILADELPHIA (TNS) — The ominous mailer has an image of Doug Mastriano on one side. The other has a clipping from a news article reporting that the state senator wanted the federal government to suspend privacy laws so local health departments could “release names and locations” of COVID-19 patients.

”We can’t trust Doug Mastriano,” warns the mailer, which was paid for by a well-funded conservative political group and sent to Republican primary voters this week.

The attack was the clearest sign yet that most Pennsylvania Republican insiders see Mastriano, one of the state’s leading election deniers, as the front-runner for the party’s nomination for governor — and are increasingly worried about it.

Less than three weeks before the May 17 primary election, polls and interviews with campaign advisers and other GOP insiders suggest the nine-candidate race remains a tossup. The share of voters who say they are undecided — as high as 40%, according to an April Franklin & Marshall College survey — is unusually high this late in the campaign. That might be partly because it’s the biggest GOP gubernatorial primary field since 1978, when Dick Thornburgh won with just 33% of the vote.

Campaign aides say this year’s winner could prevail with as little as 28%.

Voters this year have endured a deluge of TV ads, many of them negative, especially in Pennsylvania’s Republican Senate primary, the most expensive in the country. That’s likely making it harder to get voters’ attention in the homestretch — and to change the dynamic of the race.

THE LEADERS

Mastriano and former U.S. Rep. Lou Barletta have led public polls for most of the campaign.

Former Delaware County Councilman Dave White and former U.S. Attorney Bill McSwain are also in the hunt. White met with former President Donald Trump, whose endorsement in the race is highly coveted, at his Mar-a-Lago resort in Florida on Tuesday, according to three people familiar with the matter.

And Trump’s declaration of political war against McSwain earlier this month — the former president called him a “coward” for not prosecuting voter fraud in 2020 — hasn’t knocked McSwain out of the race. On the contrary, McSwain is far outspending his rivals on television in the final weeks.

State Senate leader Jake Corman, who almost dropped out of the race this month before Trump apparently persuaded him to stay, has struggled to compete with the top tier.

”It seems to be coming down to Doug Mastriano or myself. It’s a close race,” Barletta said Thursday during a meet-and-greet event near the Poconos. Trump’s endorsement, he said, “can definitely swing an election.”

LARGELY AGREE

As a debate on Wednesday showed, the leading candidates largely agree on the issues. They say Democratic Gov. Tom Wolf, who is term-limited, badly mismanaged the pandemic, harming businesses and infringing on personal freedom. They want to eliminate no-excuse mail voting, enact new abortion regulations, drill for more natural gas, lower taxes, and expand access to charter schools and other alternatives to traditional public schools.

So the campaign mostly hinges on which candidate voters know the most and trust the most. And Mastriano is leading the pack, according to recent public polls and internal GOP surveys.

Mastriano, a retired Army colonel elected to the state Senate in 2019, has already outperformed the expectations of some who dismissed him as a fringe candidate with a core but small group of supporters. Some in the GOP now worry the party blew its chance to coalesce behind an alternative candidate who would stand a better chance of beating presumptive Democratic nominee Josh Shapiro, the state attorney general, in the general election.

He played a leading role in efforts to overturn Trump’s 2020 defeat in Pennsylvania, and party leaders worry his penchant for associating with fringe groups — like his decision to speak this month at an event promoting the QAnon conspiracy theory — could jeopardize Republican majorities in the state legislature. The congressional committee investigating the Jan. 6, 2021, attack on the U.S. Capitol subpoenaed Mastriano in March for documents and testimony about his involvement in efforts to overturn the election.

Mastriano said he went to the “Patriots Arise” event to speak with his constituents and described news coverage as unfair. “People across the state are sick and tired of being labeled something because you disagree with them politically,” he said during the debate.

The state GOP declined to endorse a candidate at its winter meeting. “Now it’s coming home to roost,” said a Republican insider with close ties to party leadership.

A well-funded campaign to stop Mastriano is now underway. The question is whether it’s too little, too late.

Commonwealth Leaders Fund, a conservative group that has spent about $6 million boosting McSwain’s campaign, paid for the mailers criticizing Mastriano’s March 2020statements. The group declined to say how much money it’s committing to the effort. McSwain’s campaign is also attacking Mastriano on the issue in TV ads.

When McSwain brought it up at the debate, Mastriano replied: “Nonsense is still nonsense, especially when it’s spoken from an attorney.”

”Josh Shapiro is rooting for Doug Mastriano and Teddy Daniels to win the Republican primary. They are his best shot at winning in November,” said Matt Brouillette, the PAC’s treasurer, referring to Mastriano’s chosen running mate for lieutenant governor, whose wife has accused him of domestic abuse.