Rep. Andy Kim (D-Moorestown) has picked up another county party endorsement in the Democratic primary for U.S. Senate, this time in Sussex County in the rural northern reaches of New Jersey.

At their convention this morning in Stanhope, Sussex Democrats awarded their official party endorsement to Kim over First Lady Tammy Murphy by a vote of 101-76 (57%-43%), with one vote for former Newark school board member Larry Hamm.

No votes were cast for a fourth candidate, Patricia Campos-Medina. Incumbent Senator Bob Menendez, who is under federal indictment on corruption charges and has been abandoned by nearly every Democrat across New Jersey, did not participate.

Kim’s win means the congressman has now prevailed at four straight party conventions against Murphy. He previously won county party endorsements in Monmouth, Burlington, and Hunterdon Counties, each by large margins; Murphy won an endorsement from Democrats in Passaic County, but that was decided by top party leaders rather than at a true convention.

Unlike those four prior counties, though, the Sussex endorsement doesn’t carry with it a county line, the unique New Jersey institution that places party-endorsed candidates in the same row or column. Kim’s Sussex win means only that he will carry the official slogan of the Sussex County Democratic Committee on primary ballots.

Sussex County is strongly Republican, but its county Democratic organization is one of the state’s most progressive, with an independent-minded county committee and a new chairwoman in Zoe Heath. Its influence is limited, though, by its small population, accounting for only around 1% of the statewide Democratic primary electorate.

Prior to the convention, Kim had announced endorsements from six municipal Democratic committees in Sussex County, while Murphy did not release any endorsements of her own. Kim’s victory, then, does not come as a surprise, and Murphy arguably did better than might have been expected given the county’s political demographics. 

Still, a win is a win – and it marks a fourth straight convention loss for Murphy, who has the support of most top state Democrats but who has struggled to break through among the Democratic rank-and-file in many counties. Her losing streak is likely to continue tomorrow, when Democrats in Warren County meet to decide their own line; Warren Democrats are similar to their counterparts in Sussex, but they have a county line to award.

On Monday, though, Murphy is favored to notch her first convention win in Bergen County, a massive suburban county with a significantly more robust Democratic organization. Kim has made the convention more competitive than was initially expected, but Murphy has the public support of the Bergen Democratic chairman and nearly every prominent elected Democrat across the county.

The eventual Democratic primary election is still three months away, but thanks to the power of the party line, the endorsements awarded now will play a significant role in its outcome. That is, unless a judge rules in Kim’s favor on a lawsuit filed this week arguing that the party line is unconstitutional – a ruling that would upend New Jersey politics far beyond just the race for Senate.