In Ackerman's district that is now 40 percent Asian and also heavily Jewish, Democratic state Assemblywoman Grace Meng is vying to become the first Asian-American member of New York's congressional delegation.

Meng's Democratic rivals include state Assemblyman Rory Lancman, who has made support of Israel a central issue in the campaign, and City Councilwoman Elizabeth Crowley, who is hoping for a strong turn-out among her working-class voter base.

In the district that Towns has represented since 1983, state Assemblymen Hakeem Jeffries is touting his record of legislative achievements in the Democratic race against City Council Charles Barron, a former Black Panther who has strong support in some of Brooklyn's poorest areas, including East New York.

While Jeffries has won the endorsements of much of the Brooklyn political establishment, and his fund-raising has dwarfed that of Barron's, Barron has the support of Towns and the city's public employees union.

On the Republican side, three candidates are locked in a race to face U.S. Senator Kirsten Gillibrand in November: Congressman Bob Turner, who last year won an upset victory to replace liberal Congressman Anthony Weiner; attorney Wendy Long, who won the Conservative party nomination, and Nassau County Comptroller George Maragos.

While voters approve of Gillibrand's job performance by a margin of six in 10, more than three-quarters of voters said they do not know enough about her Republican rivals to form an opinion of them, a Quinnipiac University poll found last month.

Primaries are also being held on Tuesday in Utah, Colorado and Oklahoma, while South Carolina will hold primary runoffs for both parties for a newly-drawn congressional seat.

(Editing by Philip Barbara)