(CNN) - As New Jersey's Republican Senate nominee stands shoulder to shoulder with Garden State Gov. Chris Christie, a new poll indicates he trails Newark Mayor Cory Booker by double digits in October's special election.
According to a Monmouth University/Asbury Park Press Poll released Tuesday, Booker leads Steve Lonegan 54%-38% among those likely to vote in New Jersey's Oct. 16 special election. The survey was conducted Thursday through Sunday, following landslide primary victories last week by both Booker and Lonegan, the former mayor of the northern New Jersey town of Bogota, in the Democratic and Republican Senate primary contests.
A Quinnipiac University poll conducted at the beginning of the month, prior to the primary elections, indicated Booker with a 25 percentage point lead over Lonegan.
The new survey's release comes hours before Christie, who's running for re-election this year, will endorse Lonegan, the man he beat four years ago for the state's Republican gubernatorial nomination. Senior officials for both the Christie and Lonegan campaigns Monday confirmed to CNN that the event would take place Tuesday afternoon at the Hunterdon County GOP headquarters in Flemington, New Jersey.
That Christie is endorsing Lonegan was expected. That Christie is giving his support in person is somewhat unexpected, as conventional wisdom is that the governor would try to keep his distance from the more conservative Lonegan. Christie is trying to score an impressive re-election victory in November with the support of not only Republican but also Democratic and independent voters in New Jersey. Christie's 2013 re-election bid is also increasingly seen as a testing ground or launching pad for a possible 2016 bid for the White House.
Christie also has a strong working relationship with Booker. A victory in the October contest would make Booker the first African-American elected to the Senate since Barack Obama in 2004. The winner of the election will finish the term of the late Democratic Sen. Frank Lautenberg, who died earlier this year.
According to the poll, Booker has the backing of more than nine in ten Democratic voters, with Lonegan grabbing the support of nearly eight in ten Republicans. Independents appear split, with 43% for Booker and 41% for Lonegan.
While the overall horserace number is little changed from a pre-primary poll conducted in June, Booker's double digit advantage among independents has disappeared.
Booker's favorable rating has edged down slightly, from 61% in June to 57% now. Twenty-three percent of those questioned say they have a unfavorable view of Booker and one in five have no opinion. The survey indicates Lonegan is not nearly as well known as his opponent, with a 31%-20% favorable/unfavorable rating and nearly half of those questioned saying they don't know enough about him to form an opinion.
"Cory Booker appears to be in the driver's seat after his big primary win, but his personal ratings declined over the course of the campaign. Steve Lonegan, on the other hand, remains basically unknown to half the electorate after coasting to the GOP nomination," said Patrick Murray, director of the Monmouth University Polling Institute. .
The Monmouth University/Asbury Park Press Poll was conducted August 15-18, with 696 New Jersey voters likely to cast ballots in the October special election questioned by telephone. The survey's overall sampling error was plus or minus 3.7 percentage points.