Republican Steve Lonegan is going to mount an improbable win in New Jersey, he said, because the special Senate election there will be a referendum on President Obama and his healthcare law.

And he believes his win will be the key to overturning ObamaCare.

"The election on Oct. 16 is a national election because it's going to be an all-out referendum on Obama — on ObamaCare," he told The Hill in a phone conversation on Tuesday.

"When we win, it'll just be earth-shaking."

He called for Republicans in Washington to "hold the line" on the shutdown until Election Day, Oct. 16, because, he said, his win will offer them the momentum they need to fully overturn ObamaCare.

"Hold the line, hold the line on this government shutdown if that's what it takes. When I win on October 16, the following day Democrats are going to fold," he said.

"It's going to be a powerful message. It's going to be a loud one, it's going to give the Republican Party the energy they need to work even harder to repeal ObamaCare."

The former Bogota, N.J., mayor and outspoken conservative remains the heavy underdog in the deep-blue state, which went for President Obama with nearly 60 percent of the vote in 2012.

But two consecutive polls have shown a tighter race than expected, prompting questions about Booker's standing.

Democrats believe, regardless of whether Booker is suffering a loss of support, that there's no way Lonegan can win with the national GOP brand around his neck, particularly as an unpopular government shutdown paralyzes Washington.

Polling has shown that Americans oppose the shutdown, and that Republicans would receive much of the blame for it.

But Lonegan called the shutdown "a big yawn," and noted that all of the local and state government in New Jersey was still running.

"It's a few areas of the federal government [shut down] that are slightly inconveniencing some people. It's not a big price to pay to fight this fight right now," he said. "There's some government employees that aren't getting paid that will probably end up getting paid anyway. I'm sorry if there's inconvenience for some."

He said he's not concerned about how activities, or a lack thereof, in Washington will affect his reelection fight, as he believes voters will realize Democrats are at fault and the shutdown must occur.

"Americans are realizing very, very quickly that this shutdown is necessary," he said.

The  Republican appears to be gaining some steam in the final weeks of the campaign, as two consecutive polls show Democrat Cory Booker's lead down from the mid-20s and 30s to low double digits.

Much of that shift is due to the way the polls were conducted, but some of Lonegan's attacks on Booker's perceived celebrity appear to be taking their toll.

Lonegan said that he wasn't surprised by the new polling because he had been “working absolutely as hard as possible ... pounding away on our message, exposing Cory Booker for what he is.”

Lonegan said Booker is “not the big mythological candidate” that Democrats have touted.

“He made the tragic error of thinking he was the anointed candidate and spent two weeks running around California with the Hollywood elite,” Lonegan said.

Booker has been dogged as well by negative press in recent weeks focused on his engagement in a tech startup, homes he owned in Newark, an apparently composite character he uses on the campaign trail and flirtatious interactions he had with a stripper on Twitter.

Lonegan said he believed the polling showed a tighter race because his own message was resonating with voters and because "all these myths about Booker are melting, turning out to be either embellishments or pure lies."

It will be difficult, however, for Lonegan to cut into Booker's double-digit lead in just two weeks, particularly in a state as Democratic as New Jersey.

Lonegan was confident that the debates could help him close that gap, as Booker, he said, "is not going to know how to answer real questions" on economic policy issues and his record as mayor of Newark.

"He can bring his notes with him, he can bring his teleprompter, he can have a lifeline, I really don't care. I'm going to beat this guy on the issues," he said.

"By the time I'm done with Cory Booker, he's going to wish he never went into politics," Lonegan added.