But a Monmouth University poll out earlier in the day showed a 10-point lead for Booker, much tighter than many expected. That margin is similar to recent surveys from Quinnipiac University and Richard Stockton College, which found Booker with 11- to 12-point leads.
The likely difference: No one is quite sure how to predict voter turnout, given the odd midweek, mid-October special election. The biggest question in the race is who gets their voters to the booths.
The confusion of having a Wednesday election was unwittingly illustrated by the Republican National Committee on Monday, when it sent out an erroneous tweet urging people to go to the polls Tuesday. The committee quickly corrected itself, but the message was a reminder of how rare it is for people to think about a Wednesday vote.
The polls do find some common ground in the damage the race has done to Booker. Each found Booker's unfavorability ratings soaring, as Lonegan pounds his record in Newark and questions his authenticity. In both polls, Booker is increasingly seen as an ambitious self-promoter - though more voters agree with his positions on the issues.
Lonegan also has suffered, though, as voters learn more about his views. In particular, the Rutgers poll found that independents who watched the two Senate debates favored Booker 59 percent to 37 percent, while independents who did not watch came down in favor of Lonegan, 45-42.
In the debates, Lonegan staked out hard-right positions on a number of issues despite New Jersey's leftward lean.
Even with the smaller gap - 10 points - Booker is still heavily favored. But given Booker's political star power and the factors in his favor - more money, more name recognition, a strongly Democratic state, and an opponent with staunchly conservative views - most observers had expected a bigger win for the Newark mayor. (Though most politicians would be happy with a 10-point victory.)
The Rutgers poll sees Booker with an even bigger win, though: It said likely voters favor him, 58-36.
"Voters we talked to seem to have moved back in his direction," said David Redlawsk, director of the Rutgers-Eagleton Poll. "The debates presented a stark picture of the differences between the candidates, which appears to have led independents to prefer Booker."
Booker had a 54 percent positive rating, but that was down nine points from Rutgers' early September poll. His unfavorability has grown to 32 percent (from 19 percent), and 34 percent see Booker as mainly concerned with self-promotion.
Still, 48 percent of voters said his campaign makes them feel hopeful, and 47 percent believe he has made progress as mayor of Newark.
Lonegan's favorables were up eight points to 30 percent, but his unfavorable ratings have climbed even more: to 34 percent from 22 percent on Sept. 11.
Despite Booker's being seen as more in step with New Jersey's views, independent voters preferred Lonegan, 48-43. That's an 11-point swing; two weeks ago, Booker led 46-40 among independents.
Lonegan has hurt Booker by raising questions about his motivations.
"Concerns about Cory Booker's intentions to serve New Jersey continue to persist, and his favorability ratings continue to drop," said Patrick Murray, director of the Monmouth University Polling Institute. "At the same time, voters clearly prefer Booker's political views over Lonegan's. The message seems to be that Garden State voters don't like to feel that their support is being taken for granted."
A plurality of 48 percent told Monmouth that Booker's main attraction is the national spotlight, compared with 37 percent who say his focus is on New Jersey.
The Rutgers poll sampled 513 likely voters with a margin of error of plus or minus 4.3 percentage points. The likely voters were from a sample of 798 registered voters polled statewide using live callers to landline and cell phones from Oct. 7 to Sunday.
The Monmouth poll surveyed 1,393 likely voters. The poll was conducted by telephone from Thursday to Saturday and has a margin of error of plus or minus 2.6 percentage points.