Jack Ciattarelli’s argument is simple.

He repeatedly spotlights that he’s the only Republican who can defeat Democratic Gov. Phil Murphy of New Jersey in this November's election.

Ciattarelli, a former GOP Assembly member who ran unsuccessfully for the 2017 Republican gubernatorial nomination, is the front-runner this time around, as New Jersey holds its primary Tuesday.

CIATTARELLI TOUTS HE'S THE ONLY REPUBLICAN WHO CAN BEAT MURPHY

"To beat Phil Murphy, we need to nominate the strongest candidate," Ciattarelli emphasized in a video posted to social media on the eve of the primary election. "I’m the only candidate with the fundraising ability to defeat Phil Murphy and his extremist agenda."

Ciattarelli has dramatically outraised his three rivals for the Republican nomination – conservatives Hirsh Singh, who unsuccessfully ran for U.S. Senate last year, and Phil Rizzo, a pastor and former real estate developer – as well as Brad Levine, a former Franklin mayor and Somerset County freeholder who is considered a more moderate contender.

Pointing to his impressive fundraising haul during an interview last month with Fox News, Ciattarelli highlighted "what it tells me is people like what they see and hear from me and my campaign. I think we made the case that there’s only one Republican that can beat Phil Murphy in November, and that’s Jack Ciattarelli."

Ciattarelli came in second in the 2017 GOP primary to then-Lt. Gov. Kim Guadagno, who lost to Murphy in the general election by double digits. The few polls that have been conducted in the race indicate Ciattarelli leads his rivals. 

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But a major factor weighing on the primary is former President Trump, who spends the summer at his Bedminster golf club in New Jersey and who remains extremely popular with Republicans in the Garden State and across the country.

Patrick Murray, polling director of the Garden State-based Monmouth University Polling Institute, said the primary is "going to be key indication of how strong the Trump wing of the party is in New Jersey, where the moderate of image of Republicans has really been the key to their success in the past statewide." He said that the results may tell us "whether the old-guard moderate Republican Party of New Jersey still holds sway."

Ciattarelli, a certified public accountant who started a medical publishing company, faces criticism that he’s not supportive enough of the former president.

"When you’re a gubernatorial candidate, there’s always going to be one type of criticism or another," he said in his Fox News interview. "My focus is on Phil Murphy. And here's one thing I know about all 1.4 million Republicans in New Jersey, none of them want to see Phil Murphy get a second term. It’s my job to get all of us to rally around that very point."

Asked if he'd seek or accept Trump’s endorsement, Ciattarelli answered that "there's only one endorsement I seek, and that's the endorsement of the voters of New Jersey. That's the only one that matters. So that will continue to be my focus."

Singh is keeping Trump directly in the primary spotlight, running as an enthusiastic supporter of the former president. He repeatedly has made unfounded claims that Trump won last year’s presidential election.

"I’m not afraid to say it, President Trump won in 2020.," he tweeted on Monday. "Vote for pro-Trump Hirsh Singh on June 8th if you stand with President Trump and want to help us make New Jersey Great Again."

Singh finished a distant third in the 2017 GOP gubernatorial primary behind Guadagno and Ciattarelli but lost last year’s Republican Senate nomination by only two points. 

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Rizzo, who along with Levine is considered a long shot for the nomination, is also an enthusiastic Trump supporter. He tweeted a photo of himself with the former president at a fundraiser at Trump’s Mar-a-Lago resort in Palm Beach, Fla.

Trump has stayed neutral in the Republican primary race. After a bogus Trump statement endorsing Singh this past weekend started spreading on social media, Trump adviser Jason Miller tweeted, "This posting is FAKE. President Trump has NOT endorsed in the race for Governor in New Jersey."

And Singh on Monday emphasized that "Myself and my campaign have NOTHING to do with this. This is a complete distraction meant to damage our campaign."

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Because Ciattarelli has won the endorsements of all 21 Republican county organizations in the state, he’ll grab the prime position on the GOP ballots statewide, which will likely win him some votes Tuesday. There won’t be a runoff – as the candidate who captures the most votes wins the nomination. 

"The system is New Jersey’s primaries is set up to basically hand the nomination to whomever party leaders feel should get it. But with a low-turnout race where only about 250,000 Republicans will show up, it’s possible that the Trump wing of the party is significantly large enough that it could upset the natural order of things in New Jersey," Murray noted.

Phil Murphy, New Jersey's governor, speaks at a news conference after touring the New Jersey Convention and Exposition Center COVID-19 vaccination site in Edison, N.J. on Friday, Jan. 15, 2021. (Mark Kauzlarich/Bloomberg via Getty Images)

Phil Murphy, New Jersey's governor, speaks at a news conference after touring the New Jersey Convention and Exposition Center COVID-19 vaccination site in Edison, N.J. on Friday, Jan. 15, 2021. (Mark Kauzlarich/Bloomberg via Getty Images)

But regardless of who wins Tuesday’s GOP primary, it will be an uphill climb against Murphy in the blue state of New Jersey. Democrats have a roughly 1-million-person advantage among registered voters, and President Biden carried the Garden State by 17 points last November over Trump. Murphy is running unopposed for the Democratic gubernatorial nomination.

Murphy's record - especially how he handled New Jersey's response to the coronavirus pandemic - which severely impacted the state - will be a top issue in the general election, as it was in the primary campaign.

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Polls are open until 8 p.m. in the Garden State, and mailed-in ballots need to be postmarked by 8 p.m. Tuesday to count. New Jersey has an open primary system, meaning independents – there are more than 2.4 million unaffiliated voters in the state – can cast a ballot in either the Democratic or Republican primaries.

The primaries are grabbing national attention, as New Jersey and Virginia are the only two states to hold gubernatorial contests in the year after a presidential election.