NJ Senate race pits first lady against lawmaker, testing one of the last big political machines: Experts

New Jersey's Senate race is offering voters a choice between a congressman, a first lady and, possibly, a sitting senator indicted on corruption charges that he denies.

But more than anything, some experts say, the Democratic primary contest on June 4 could be a gauge of the endurance of a largely bygone era of machine politics in an increasingly populist age.

Rep. Andy Kim and New Jersey's first lady, Tammy Murphy, are running for the seat of Sen. Bob Menendez, who has denied wrongdoing after being indicted on charges including corruption and still hasn't publicly said if he'll run again or not.

Because of New Jersey's Democratic tilt, the eventual nominee will be the favorite in November's general election.

Kim is touting a grassroots campaign in the primary, while Murphy, a former Republican with immense personal wealth, is flexing her connections to some of the state's power brokers, who have a heavy hand in shaping local races, including through helping set the ballot order.

But Murphy's battle with Kim is stressing that unusual election system, in which county party chairs hold outsized influence in deciding who gets placed on what's known as the "line," the prominent physical column on the ballot that's a premium location for all endorsed candidates -- who otherwise get placed in what one critical group termed "ballot Siberia."

The bureaucratic-sounding decision is thought by some to have outsized importance because candidates on the line are seen first, while others can be arranged in other, less notable parts of the ballot.

Some counties delegate ballot placement by a voting convention of elected delegates and others assign it based solely on county party chairs' endorsements -- a system that detractors decry as ripe for favoritism.

"We are absolutely seeing a test of how powerful the machines still are or how much residual power they have or how much they don't have," said Micah Rasmussen, the former press secretary for ex-Gov. Jim McGreevey, a Democrat. "We are seeing the power of the organizations to pick the winner and whether or not primary voters are going to say, 'Thank you very much, but we can decide for ourselves.'"

Some observers have noted that the race is also taking place at a time when national politics is still being transformed by rising populism on both sides of the aisle through figures like former President Donald Trump and Sen. Bernie Sanders, a Vermont independent, who tout messages and policies taking aim at the "swamp" or the wealthy "elite."

Kim has looked to seize on that national sentiment by essentially running against the line itself.

On the stump, the congressman casts himself as a fighter against the political machine and Murphy as a member of that system, trying to turn her wealth and access to the governor and his allies against her.

He also filed a lawsuit against various county election officials trying to eliminate the unique balloting system, arguing it is "fundamentally unjust and undemocratic." A court hearing is scheduled for Monday.

In an interview, Kim said he had been "blown away by the energy that's out there right now" and that his campaign has become about "much more than just about the Senate."

"I think people are, just below the surface, bristling at this," one longtime New Jersey operative, who asked not to be quoted by name to be more candid, said of the ballot structure and the idea that Murphy is boosted by her husband's position. (Murphy's campaign did not make her available for an interview with ABC News.)

"His [Kim's] running against the line resonates with über progressives who have never had a seat at the table, African Americans who have not had an adequate seat at the table and women, who definitely haven't had a seat at the table," the strategist said. "It's a real sweet spot as an outsider."

Murphy, meanwhile, has waged what some operatives likened to a grasstops rather than a grassroots campaign. The first lady has racked up endorsements from prominent party chairs in Middlesex and Essex counties, two of the state's largest, where ballot placement is based solely on the chair's endorsement rather than a nominating convention.

Her allies have also painted Kim as inauthentic, pointing to his accepting of the line in his past congressional runs and in counties now where he won it.

"Kim is not a credible messenger on the line," said one source familiar with Murphy's strategy. "He likes the lines he wins and dislikes the lines he loses."

The dueling strategies are understandable: Past research has suggested that the line -- which comes along with canvassing and other structural support stemming from a county party endorsement -- can improve a candidates' chances.

But other operatives were skeptical the edge is all that steep, though they agreed an advantage exists.

"I can tell you, it's really hard to run off the line. The line is a listing of the candidates who the county party has endorsed, and it is all the familiar names. So, if you're running off the line, you're liable to be partnered up with a bunch of people who people have ... never heard of or have only heard of because they're gadflies, and so it's a hard thing to do to run off the line," said the longtime New Jersey political operative.

The candidates' respective playbooks have paid dividends for each of them so far.

Kim has won many early nominating conventions in smaller counties and led Murphy in a recent Monmouth University poll, which he touted as indicative of his bottom-up support.

The first lady, meanwhile, is set to appear on the line in Middlesex and Essex Counties as well as in Bergen County after a recent key win at the nominating convention there -- clinching the line in the state's three largest counties.

"We are now settling in for a fight to the finish," Rasmussen said. "From here on in, the main question now becomes how hard the machine organizations will work for Murphy while at the same time Kim’s grassroots supporters have shown they are willing to walk over broken glass to vote for him."

Advocates of the current system argued that it's appropriate for county parties to offer an imprimatur to tell voters who deserves to carry the party mantle into November.

But others warned that it makes Kim's headwinds even fiercer and elections susceptible to "abuse," particularly in a cycle when many county chairs have business in front of the state government, led by a governor who has outsized sway in doling out a slew of plum jobs. All statewide positions are appointed, outside of the governor and two senators, not to mention other jobs in Trenton.

That leaves only what one prominent state politician framed as a rage-against-the-machine strategy that "a lot of people are afraid" to enact.

"There is an understood, unspoken underpinning to these negotiations on the backing that they will be able to either continue or further their relationship with the current administration. So, that's the big question here -- not just the county line but then also Tammy Murphy's current position, her husband's current position and the connections that affords," said New Jersey pollster Ashley Koning, of Rutgers University.

On top of that, Kim is mostly known is south New Jersey, where his congressional district lies. Murphy's power base, meanwhile, is in the more populated north, where Kim will inevitably have to make deeper inroads.

"What he's got to do is he's got to make the case that it is worth finding him on the ballot .… [that] if you're committed to him, you want to take the time to find him on the ballot. So, there's a little bit of voter education going on," Rasmussen said.

Still, Kim boasted that he'd "rather be me on all accounts" than Murphy. And with the race as close as it is, observers are viewing it as a test of whether the New Jersey system will survive or go the way of machines of yesteryear, like those in New York or Chicago.

"It's certainly a test of how New Jersey politics works and how populist politics work if we're looking at a broader national trend," said Koning. "I think this is precipitously becoming one of the biggest tests of that county line and really showing the juxtaposition of the internal political machine and the inside baseball of politics versus the more grassroots, populist version of politics that a candidate like Andy Kim might represent."