Booker takes a large majority of Democrats, 92 percent, while Lonegan takes only 79 percent of Republicans. Independent voters split 43 percent to 41 percent for Booker.
Those numbers and his favorables are an indication the primary campaign may have hurt Booker's standing in New Jersey, as he's lost some support among independents and his unfavorables have increased since June.
In that June poll, Booker took 48 percent of independents. And then, only 15 percent of respondents viewed him unfavorably; now 23 percent of respondents view him unfavorably.
Booker easily won the Democratic primary and is the heavy favorite to take back the seat in the general election in October. But a steady drip of negative press about his connections to the tech and financial worlds, as well as his career as an attorney and entrepreneur, seem to have taken a bit of a toll on his image and his support among skeptical independents.
The new Monmouth University poll also indicates voters largely see him as a more of a typical politician, rather than the innovative problem solver he attempted to establish himself as during the primary campaign.
Ultimately, however, the blue tint of the state is likely to leave a clear path to the Senate for Booker, and voters don't seem particularly open to buying Lonegan's arguments against Booker, which hinge on President Obama's healthcare law.
Forty-nine percent of likely voters approve of Obama's job performance, more than the 43 percent that disapprove, and a plurality, 47 percent, say they don't want their senator to vote to overturn the health care law, as Lonegan has pledged to do.
The survey was conducted among 696 likely New Jersey voters from Aug. 15-18 and has a margin of error of plus or minus 3.7 percentage points.
Poll: Booker holds early, substantial lead over GOP challenger
The Monmouth University/Asbury Park Press poll gives Booker 54 percent support among likely voters, while Lonegan takes 38 percent support.