"I encourage voters in New Jersey to give Steve a look and not believe those in the media who tell us conservatives can't win in certain areas," Palin's statement said.
The former Alaska governor plans to push Lonegan's candidacy through social media, though she is not expected to visit New Jersey on his behalf.
"I am honored to receive the endorsement of such a principled leader," Lonegan said. "Gov. Palin has been more than a voice for traditional American values; she has been a leader in helping conservatives stand up for their ideas and win elections."
Lonegan can now boast endorsements from stars of the right including Palin, Texas Gov. Rick Perry, and Kentucky Sen. Rand Paul.
But while they are likely to boost enthusiasm among hard-core Republicans, they may also make it harder to win over Democrats, who outnumber Republicans in New Jersey by 730,000 voters.
"If voters had any doubt about how out of touch Steve Lonegan's values are with the values of most New Jerseyans, Sarah Palin's endorsement puts that to rest," Kevin Griffis, a Booker spokesman, told the Newark Star-Ledger. "Like Mr. Lonegan, she wants to ban abortions even in cases of rape and incest, doesn't believe in climate change, and opposes commonsense measures to make our streets safer, like expanded background checks for gun purchases."
The special election for the Senate seat is Oct. 16.