Despite the advantages, political analysts say Tammy Murphy holds in the race.

Congressman Andy Kim has shown himself to be a formidable challenger with his grassroots support and a recent lawsuit that's trying to dismantle the controversial party line system.

This week, four county clerks responded to that suit with a decisive message, saying it's too late to intervene without upending the June primary election.

Senior correspondent Brenda Flanagan has the latest.

That's always the answer, is do it some other time.

But it is all about timing for U.S. Senate candidate Andy Kim.

He filed a federal lawsuit this week against 19 county clerks to change Jersey's ballot system in time for the June 4th primary.

Kim Suit calls the current county line ballot fundamentally unjust and undemocratic.

A judge will hear the case March 18th, when the clerks will argue it's way too late to make such major ballot changes.

Mr. Kim's gotten himself the moniker Mr. Day Late and Dollar Short, commented defendant's attorney John Carbone.

Where the hell is he been?

I've sought to have changes.

I've asked for dialog and discussion about this and I've gotten no response.

And as a result I've decided I have to take action through this legal route because we've gotten no other engagement from these county clerks and others.

Kim argues it's not too tight a turnaround for county clerks to redesign the ballot.

Federal Judge Zahid Qureshi promised a ruling by April six, but Carbon says there's not enough time to reprogram thousands of voting machines and mail ballots to military personnel overseas.

In a letter to Judge Qureshi, he predicted cascading and rippling effects on the election officials, candidates and voters.

It's a long shot lawsuit, says Rider's Michael Rasmussen.

I do think that he has long odds.

Look, it's been speculated that he wins either way in that he either gets the relief he's seeking or to his supporters, this is more evidence of a system that is not fair play is not evenhanded, and and it just makes them angrier and redouble their efforts to make sure that they get him elected.

He says judges also generally abide by the U.S. Supreme Court's so-called Parcelle principle, which advises not to intervene too close to an election.

Kim's won three Democratic county conventions with grassroots support so far, but his opponent, First Lady Tammy Murphy, is expected to dominate in more populous counties where she's enjoyed the early endorsement of political bosses.

Meanwhile, Murphy's launched her first campaign ad against the National Rifle Association.

This is the NRA's World headquarters.

It's where cowards work.

They know their guns are killing our kids, but they don't care.

Murphy promises to fight for universal background checks and a ban on assault style weapons.

The ad drew immediate backlash from Congressman Kim, who noted that before she left the GOP, Murphy supported Republicans who worked to weaken gun control laws.

She's someone who has donated six figure donations to Republican candidates and causes, including George W Bush, who is someone who very much led the charge on ending the assault weapons ban on a number of other pieces of legislation that damaged our ability to have the kind of gun violence prevention efforts in this country.

So the first lady needs to answer for that.

Kim says his record confirms his support for gun control.

A murphy spokesperson replied It's not surprising to see one of the most misleading and hypocritical campaigns in recent memory slam a positive message that all New Jersey Democrats should agree on.

It would be refreshing to see Andy Kim and his campaign put forward their own positive vision for New Jersey rather than attempt to tear down Tammy Murphy at every turn.

But Rasmussen thinks the criticisms are valid.

As somebody who's never held public office before her past campaign contributions, those she choose, chose to support and her voter registration are her paper trail.

County Democrats will continue to weigh in next week when Bergen holds its Democratic convention.

It's a murphy stronghold where Kim's hoping to continue his convention momentum.

I'm Brenda Flanagan.

NJ Spotlight News.