Former Assemblyman Jack Ciattarelli (R-16).

He’s running, or plans to anyway, and although he lost to Kim Guadagno last year 31-47% in the Republican Primary, he impressed on the trail with his class, poise and knowledge. He also has an authentic New Jersey narrative, and his allies in particular relish a Jack match-up with Governor Phil Murphy. The challenge will be to keep him visible and relevant in the period of time between now and 2021, and allies have undertaken a “Jack 2.0” strategy, which included a rigorous Lincoln Day Dinner scheduled and prominence at State Party Chairman Doug Steinhardt’s April 14th Statewide Leadership Summit in Atlantic City.

U.S. Rep. Tom MacArthur (R-3).

One of two BIG money names on this list, the self-funder has the immediate task of knocking off Andy Kim in this year’s general election and proving a certain implacability as he prepares for future scalable political ventures. Sources say he has at least one statewide run in him. Now, President Donald J. Trump has somewhat upstaged and blunted what might have been a more auspicious entrance for MacArthur, first elected in 2014. But he has a dogged style – and ambition. Get through Kim, and he instantly enters the discussion as a top tier 2021 choice. Weaknesses? Democrats will still dangle the Trump albatross around his neck.

Monmouth County Sheriff (and Monmouth Republican Chairman) Shaun Golden.

His allies affirm early feel-out maneuvers by the seaside lawman, an affable brand name with shore region reach. “He’s running,” a GOP source told InsiderNJ, giving a “take it to the bank” wink.

Retired Pharma Exec Bob Hugin.

A Princeton-educated veteran of the U.S. Marine Corps, Hugin’s the favorite this year to land the Republican nomination for U.S. Senate. Of course, he would need to dent U.S. Senator Bob Menendez (D-NJ) to prove the value of $40 million he promises to throw at him and lift his candidacy into the sphere of “we want him back.” Establishment Republicans are excited about Hugin. He’s had but token opposition at the county conventions. Following the candidate’s speech at Cumberland’s GOP convention last week, InsiderNJ overheard an insider remark, “If we can’t win with him, it’s over.” One interesting note about Hugin, Ciattarelli and MacArthur. Potent Jackson-based operative Chris Russell works for all three of them. If all three want to run, the four men will have to work that out among themselves.

Assembly Minority Leader Jon Bramnick (R-21)

Unencumbered now by the presence of pal Governor Chris Christie, Bramnick can relentlessly shape his own raging moderate brand. A 15-year veteran of Trenton, he knows the subterranean passageways and catacombs of Trenton as well as anybody and is one of the best liked personalities on the premises. He has the connections and the charisma, and is one of the New Jersey politicians who has most forcefully spoken out against Trump. The question is would he really want to put himself out there with a statewide run. He would also have to coordinate the statewide thing with slate mate Senate Minority Leader Tom Kean, who might also want to run.

Assemblywoman Holly Schepisi (R-39)

There’s always buzz about the 39th District Assemblywoman undertaking another frontier. Of course, it would probably senate first (when Gerald Cardinale retires), but if Cardinale were to run again in 2021, it’s not inconceivable to picture Schepisi – impatient to get out of back bench world – launching a statewide bid.

Former Bogota Mayor Steve Lonegan

If he goes down in CD5 this year (or if he wins!) he could always bounce back (or spring forward) with a movement conservative, Hell-no statewide campaign in 2021. It’s not like he hasn’t done it before, and it’s difficult to picture him not being motivated by Murphy.

Assemblyman Jay Webber

If Tony Ghee squiggles past Webber this year in the CD11 Republican Primary, or if the conservative comes up short in a general election showdown with the Democrats; and if no true conservative emerges on a statewide scale by 2021, it’s not improbable to picture Webber stepping up with one all-out statewide run.

Linwood engineer Hirsh Singh

Key components of the Republican establishment led by Ocean County Republican Committee Chairman George Gilmore got Singh out of the U.S. Senate contest this year to make way for Hugin. Now Singh appears well-positioned to land the Republican nomination for Congress in the 2nd District. But state Senator Jeff Van Drew (D-1) will be a very tough out. Singh nurses grand designs. Sources say it was difficult for him to take a knee and allow Hugin to step over him for the statewide support of the party this year. Plus, he’s already run for governor, harvesting 24,000 votes in 2017.

Former Lieutenant Governor Kim Guadagno

She could be another Barbara Buono and slip the surly bonds of Jersey. There’s also the mechanical obstacle of a very motivated and ambitious Golden in her home county, whose own statewide designs would likely box out Guadagno. It’s tough to see her getting traction to run again, but she does have a fan base. Just go to a Passaic Republican Women’s event and you’ll see.

Other Possibilities:

Former Senator Jen Beck

Hamilton Mayor Kelly Yaede