(WHTM) – Former President Donald Trump has endorsed Pennsylvania State Senator Doug Mastriano in the Pennsylvania Governor race.

“There is no one in Pennsylvania who has done more, or fought harder, for election integrity than State Senator Doug Mastriano,” said Trump in a statement on Saturday morning.

Trump, who has already endorsed Mehmet Oz in the Senate race, said “Doug Mastriano and Dr. Mehmet Oz will make an unbeatable team going into the most important Midterm Election in the history of our Country.”

Mastriano, who has reported ties to the conspiracy group QAnon and a vocal supporter of former President Trump, has led in polls with election day approaching. Despite Mastriano’s double-digit lead, Trump’s endorsement comes at a time when the candidate faces Pennsylvania Republicans voicing concern, and reportedly working to stop his surge ahead.

Mastriano said Saturday he is “delighted” to have Trump’s support.

“We were on our way to a victory Tuesday anyway,” he said. “To have the icing on the cake of course, with the endorsement of Donald Trump, we’re just delighted.”

According to Republican political consultant Christopher Nicholas, the endorsement itself is not a surprise.

“There’s no doubt that Mastriano’s been a strong proponent of President Trump’s policies, even more importantly, his attitudes,” Nicholas said.

In particular, Mastriano has been vocal about the former president’s unfounded claims of widespread voter fraud in the 2020 election.

“As the governor, I get to appoint the Secretary of State who actually on my behalf oversees the manner and conduct of election,” he said.

Trump’s false claims of a stolen election have been debunked by the courts, his own Justice Department, and numerous recounts, and no prosecutor, judge, or election official in Pennsylvania has raised a concern about widespread fraud.

The timing of Trump’s announcement, just three days before the primary, is unusual.

“Normally when you have a big endorsement, you want to roll it out as soon as you can,” Nicholas said.

However, it could still have an impact. A poll in March by WHTM/Emerson College Polling/The Hill found 61 percent of Republicans are more likely to support a candidate endorsed by the former president.

Some Republicans criticized Trump’s endorsement of Mastriano. Former U.S. Congressman for Pennsylvania Tom Marino, speaking at an event endorsing gubernatorial candidate Lou Barletta, said he is disappointed.

“Where in the hell is the loyalty? Lou and I were the first congressmen to come out to endorse trump,” Marino said.

Barletta is in second place in the polls, but candidates like Senate Pro Tempore Jake Corman and former congresswoman Melissa Hart both dropped from the governor’s race this week and endorsed Lou Barletta‘s in an attempt to coalesce around candidates Republicans believe can win in the general election.

“There are strong doubts about Senator Mastriano’s ability to attract independents and Democrats in the fall,” Nicholas said.

Dave White and Bill McSwain, who have rounded out the top four candidates in the race, each forcefully pushed back on calls to drop out and called Corman’s endorsement of Barletta a career politician endorsing a career politician.

Speaking to abc27 on Saturday, Mastriano called for unity.

“Let’s join together, take our state back and make Pennsylvania one of the greatest places in the nation,” he said.

While Trump called Oz and Mastriano “an unbeatable team,” Mastriano has endorsed Oz’s opponent Kathy Barnette, who has come under fire from Trump and others in the Republican party for her unvetted background and controversial homophobic and Islamaphobic tweets.

“I’m honored to receive the endorsement from President Trump, today,” said Mastriano. “But the honor is not for me. It’s for the millions of hard-working Pennsylvanians who want their individual liberties restored, power returned to the people, and for their elected leaders to fulfill the America First — and Pennsylvania First — agenda.”

On the campaign trail, Mastriano has vowed to eliminate “all pandemic executive orders and edicts” implemented by outgoing Governor Tom Wolf.

In February Mastriano was subpoenaed by the Jan. 6 committee for allegedly being “part of a plan to arrange for an “alternate” slate of electors from Pennsylvania for former President Trump and reportedly spoke with President Trump about post-election activities.”

The committee released its letter to Mastriano saying they “understand that (Mastriano was) present during the attack” and that he witnessed attacks on officers.

During Nexstar’s Republican Gubernatorial debate on April 28, Mastriano stated “there are no legal issues” regarding him and the Jan. 6 committee. During the debate, Mastriano also vowed to reset Pennsylvania’s voter roll, forcing all eligible residents to re-register to vote.

According to the Associated Press, “such a move is barred by the National Voter Registration Act and likely runs into significant protections under the federal — and possibly state — constitution and laws, constitutional law scholars say.”

In April Trump slammed Pennsylvania GOP gubernatorial candidate Bill McSwain, who served as his U.S. Attorney in the Eastern District of Pennsylvania. Trump claimed the former federal prosecutor did “absolutely nothing” to investigate Trump’s false claims of widespread election fraud after Democrat Joe Biden won the state in 2020.

“One person in Pennsylvania who I will not be endorsing is Bill McSwain for Governor. He was the U.S. Attorney who did absolutely nothing on the massive Election Fraud that took place in Philadelphia and throughout the commonwealth,” Trump said in a statement. “Do not vote for Bill McSwain, a coward, who let our Country down. He knew what was happening and let it go.”

Attorney General Josh Shapiro is the presumptive Democratic nominee for governor. Pro-Shapiro groups have been running pro-Mastriano ads with reports that Shapiro believes he can beat Mastriano in the fall.

“Trump just endorsed one of the most extreme and dangerous GOP candidates in the country for Governor of PA,” said Shapiro Saturday morning. “(Mastriano) wants to ban abortion and undermine elections. He attended the 1/6 insurrection and crossed police barricades. We cannot let him win.”

In 2018, Mastriano’s chief competitor Lou Barletta was the Trump-endorsed nominee for U.S. Senate in race he lost to incumbent Senator Bob Casey Jr. by over 600,000 votes. Establishment Republicans have pushed others in the race to drop out similar to Hart and Corman to prevent a Mastriano victory on May 17.

Barletta reacted to Trump’s endorsement of Mastriano in a statement Saturday morning:

“Throughout this campaign I have proved that I’m the best Republican to unite the Republican Party and defeat Josh Shapiro, and I will continue unifying our grassroots conservatives towards our shared goal. I will continue making the case to the people that I am the only candidate who can unite the party and bring victory in November. I look forward to having President Trump’s endorsement Wednesday morning.”

Pennsylvania Democrats responded by calling Mastriano The “most extreme and dangerous Republican candidate for Governor.”

“Mastriano is incredibly dangerous and the Pennsylvania Democratic Party will do all it can to ensure he doesn’t get anywhere near the Governor’s office.”