A poll released Thursday only confirmed Newark Mayor Cory Booker’s solid advantage in the New Jersey Senate special election.

Fairleigh Dickinson University found Booker ahead of Republican Steve Lonegan, 50 percent to 22 percent. Twenty-three percent remained undecided with less than two months to go, including 15 percent of Democratic respondents and 23 percent of Republicans.

Booker and Lonegan won their respective primaries on Aug. 13 by wide margins. They’re facing off in the Oct. 16 special election to replace the late Sen. Frank R. Lautenberg.

Although his support was not in question, President Barack Obama formally endorsed Booker last week. Lonegan knows he’ll need some help from the national party to win in this Democratic-leaning state, which hasn’t sent a Republican to the Senate in four decades.

The poll of 700 registered voters was conducted Aug. 21-27. It had a 3.7-point margin of error.