TRENTON -- Starting Saturday night, Democrat Jim Johnson will be the second candidate with television ads in the New Jersey governor's race, NJ Advance Media has learned.

Johnson, a dark-horse candidate for his party's nomination to succeed Republican Gov. Chris Christie, will see his first TV ad air during a commercial break from NBC's "Saturday Night Live," according to his campaign.

So far, Phil Murphy, the millionaire former Goldman Sachs banking executive who is considered the early favorite for the Democratic nod, has been the only candidate airing costly TV spots in the crowded race. Most of the other candidates have posted videos online only.

But Johnson, who served as a U.S. Treasury undersecretary under then-President Bill Clinton in the 1990s, is now launching a seven-figure statewide cable and digital ad buy targeting Democratic primary voters, his campaign said.

Johnson, who was little known in New Jersey politics until this race, is bolstered by the fact he was the first candidate to qualify for the state's public matching fund program -- in which contenders receive $2 in matching public money for every $1 dollar they raise. Candidates must raise $430,000 to qualify.

"Getting on TV this soon to communicate directly to the people of New Jersey is what publicly financing a campaign is about," Jocelyn Steinberg, Johnson's recently announced campaign manager, said in a statement.

"It's not about making backroom deals with party bosses and special interests or having millions of dollars -- it's about having the ability to start a discussion with voters about the issues that matter to them," Steinberg added.

That comment appears to be a knock on Murphy, who has lent his campaign at least $10 million and has earned the support of numerous county party chairs across the state.

Johnson's spot is a minute long and introduces his background -- how his family almost lost their home when he was young, how he worked to graduate from Harvard Law School, and how he served in Clinton's administration.

It also pushes his campaign's message that Johnson -- who has never been elected to office -- is the kind of outsider that New Jersey needs in charge.

"I'm operating against a set of machinery that's been in place for a very, very long time," Johnson says in the ad. "We should change that."

Johnson's ad comes just days after Murphy unveiled his fourth TV ad of the election so far, highlighting how he, too, vows to fight "special interests" in Trenton.

In the ad, filmed at the Tops Diner in East Newark, Murphy -- who also have never held elected office -- says he'll create new jobs by growing the economy, making college more affordable, and guaranteeing equal pay.

"The special interest politicians who broke New Jersey can't fix it," he says to the camera. "But together, we can."

Numerous other candidates are also running in the Democratic primary, including state Sen. Raymond Lesniak (D-Union) and state Assemblyman John Wisniewski (D-Middlesex) -- both of whom are also claiming to be outsiders of the political establishment despite their decades in the New Jersey Legislature.

But buying statewide TV airtime in New Jersey is expensive because of the need to reach both the costly New York and Philadelphia media markets.

And as Politico New Jersey highlighted in a story this past week, many contenders are struggling to raise enough money qualify for the state's public matching fund program, which would provide them with an infusion of cash.

Only one other candidate -- Lt. Gov. Kim Guadagno, who is seeking the Republican nomination -- has announced she has qualified for matching funds. Guadagno made the announcement last week.

Brent Johnson may be reached at bjohnson@njadvancemedia.com. Follow him on Twitter @johnsb01. Find NJ.com Politics on Facebook.