New Jersey’s primary to select the candidates who will run to fill the seat of the late U.S. Sen. Frank Lautenberg got off to a wet start as severe thunderstorms drenched parts of the state.

Four Democrats and two Republicans are seeking their parties’ nominations to compete in the Oct. 16 special election. The winner will go to Washington to serve the remaining 15 months of Lautenberg’s term.

Turnout is expected to be exceptionally low in the unprecedented mid-August election, when many people are on vacation. Then there was the rain.

Nineteen people, including Democrat Cory Booker, cast ballots during the first three hours of voting at his polling place in Newark.

Booker and Republican Steve Lonegan lead in the polls.

Polls close at 8 p.m.

AP’s earlier story is below:

Low turnout was expected Tuesday as New Jersey voters decide which candidates will run to fill the seat of the late U.S. Sen. Frank Lautenberg, who died in June.

Democrat Cory Booker and Republican Steve Lonegan are expected to easily win their party primaries. Barring an upset, the two will square off in an Oct. 16 special election, with the winner headed to Washington for the remaining 15 months of Lautenberg’s term.

Turnout is expected to be exceptionally low in this unprecedented mid-August election, with many voters on vacation and heavy rain falling.

Turnout seemed on the mind of Booker as he voted blocks from his home Tuesday morning. “This is New Jersey. You’ve got to earn every single vote you get, and so polls don’t vote, people do,” said the 44-year-old, who is serving his second term as mayor of Newark, the state’s largest city. He is better known and has raised more money than three challengers, all of whom are experienced politicians but not well-known outside the areas they represent. Polls show Booker far outpacing U.S. Reps. Frank Pallone and Rush Holt and Assembly Speaker Sheila Oliver.

The final days of the campaign had Booker touring the state by bus. Actress Eva Longoria was among those campaigning with him; earlier, Oprah Winfrey held a private fundraiser for him in Jersey City.

Lonegan, 57, voted with his wife Tuesday morning in the Bergen County municipality of Bogota, where he once served as mayor and until recently was the state director of the anti-tax group Americans for Prosperity. He ran unsuccessfully for governor twice and for Congress once, and has a built-in donor network from the conservative group.

His only opponent is a political neophyte, Franklin Township physician Alieta Eck, who has never held or campaigned for elected office.

Gov. Chris Christie set the dates for the special election after Lautenberg died at age 89. Lautenberg had been a reliably liberal vote in the Senate and was its oldest member.

Pallone was endorsed by Lautenberg’s family as the candidate best able to carry on the senator’s legacy as an advocate for mass transportation and the environment. Holt was endorsed by the National Organization for Women, though it was Oliver who staked her campaign on her gender. She said New Jersey needs at least one female representative in Washington.

The state’s two senators and 12 representatives are all men.

(AP)