Newark Mayor Cory Booker won the Democratic primary in the New Jersey Senate race on Tuesday -- a victory that sets him on a clear course to become the newest U.S. senator.

With 98 percent of the precincts reporting, Booker was taking about 60 percent of the vote in a four-candidate field. Rep. Frank Pallone Jr. was second with 20 percent, while Rep. Rush D. Holt was at 17 percent and state Assembly Speaker Sheila Oliver was below 5 percent.