The Democratic nomination race to fill the late Frank Lautenberg's U.S. Senate seat isn't much of a race at all, according to the latest poll from Monmouth University.

Special Senate Election Demoratic candidates (L-R) Sheila Oliver, Frank Pallone, Cory Booker & Rush Holt (all official portraits except Cory Booker/Getty Images)

Newark Mayor Cory Booker maintains a commanding lead among voters likely to participate in the Democratic primary on August 13. Booker gets support from 49 percent of voters. Significantly fewer voters intend to vote for Congressman Frank Pallone (12 percent), Congressman Rush Holt (8 percent) or Assembly Speaker Sheila Oliver (3 percent).

"Democratic voters, really, are happy with all these candidates, but they know Booker best," said Patrick Murray, director of the Monmouth University Polling Institute. "That seems to be what's putting the race in his hands."

Murray noted that 28 percent of voters remain undecided, and the race would have the chance of becoming heated if every undecided voter decides to go with one candidate who isn't Booker.

"Our polling is indicating that there is not a likelihood of that happening," he added.

Booker has been attacked by his opponents on a number of issues, including his close relationship with Republican Governor Chris Christie, but the criticism doesn't seem to be affecting the voters.

"I don't see the potential for much of this changing, unless something hits Cory Booker," Murray said. "The only person who can beat Cory Booker in this race is Cory Booker at this point."

Both parties will choose their nominee in four weeks. The winner of the Senate seat will be chosen with a special election in October.