Tammy Murphy, the first lady of New Jersey and wife of Governor Phil Murphy, announced on Sunday that she is suspending her campaign for the U.S. Senate seat currently held by Senator Bob Menendez. The decision comes amidst criticism of nepotism and a looming court ruling on a lawsuit aimed at altering the state's controversial party-line ballot system.

In a video posted on X, Murphy explained her reasons for leaving the race, stating, "After many busy, invigorating, and yes, challenging months, I am suspending my Senate campaign today. I have been genuine and factual throughout, but it is clear to me that continuing in this race will involve waging a very divisive and negative campaign, which I am not willing to do."

Murphy's main contender in the Democratic primary was Rep. Andy Kim, who has been in office since 2019. The first lady's early endorsements from four New Jersey congressmen, just days after announcing her candidacy, had raised eyebrows and fueled accusations of nepotism.

The timing of Murphy's decision is particularly noteworthy, as it comes just days before a judge was expected to rule on a lawsuit filed by Kim, which sought to eliminate the so-called "party line" ballot structure. This system allows county leaders to give preferential placement to their endorsed primary candidates, potentially giving them a significant advantage over their opponents.

With Murphy's exit from the race, the urgency to address the primary ballot design has diminished, meaning the party-line system could remain in place for the upcoming primary election on June 4. Advocates of changing the system, such as Yael Niv, president of the Good Government Coalition of New Jersey, have questioned Murphy's motives, suggesting that her withdrawal may be a "last ditch effort to save the county line."

In her announcement video, Murphy also took aim at former President Donald Trump, calling him a "dangerous threat" and urging Democrats to unite. "As we face grave, dangerous threats on the national level, thanks to Donald Trump and far-right extremists, it's time to unify, not divide," she said. "I will now focus entirely on reelecting President Biden and ensuring Democratic victories up and down the ballot all across New Jersey."

Rep. Andy Kim, who has been backed by grassroots organizations like Indivisible, praised Murphy as "a voice for progress and public service in our state" and respected her decision to continue her work as First Lady. He also vowed to continue efforts to strengthen democracy in New Jersey while standing up against Trump's "dangerous agenda."

The suspension of Murphy's campaign comes in the wake of Senator Menendez's announcement on Thursday that he would not seek reelection in the Democratic primary due to federal corruption charges. However, the senator has left open the possibility of running as an independent in the general election, maintaining his innocence and claiming persecution by prosecutors.

CNN and Fox News contributed to this report.