The long-standing question of whether Puerto Rico should push to become the 51st U.S. state is at the center of Tuesday's gubernatorial elections in this American territory.

Former Gov. Pedro Rossello (search), whose previous terms from 1993 through 2000 were marked by a series of corruption scandals, has made the statehood demand a central theme of his campaign to return to the post.

Polls give him a narrow lead over Anibal Acevedo Vila (search), who favors the island's current status as a U.S. commonwealth. Ruben Berrios of the Puerto Rican Independence Party, making his fifth run for governor, was running third in the polls.

Puerto Rico's 4 million residents are U.S. citizens but cannot vote for U.S. president. Outgoing Gov. Sila Calderon declined to seek re-election.

Some 2.4 million Puerto Ricans were registered to vote Tuesday for governor, the island's nonvoting delegate to Congress as well as for members of the island's legislature and municipal posts.

Polls close at 2 p.m. EST. Preliminary results are expected late Tuesday.

Rossello has pledged to lead a clean government if elected again.

Acevedo Vila, who is currently the island's delegate to Congress, says he is determined to prevent the "rampant corruption" of Rossello's two terms.

Standing in a voting line at a school, accountant Enrique Vasallo said he backed Acevedo Vila because "I like the way things are" with Puerto Rico as a U.S. commonwealth.

Rossello promises another vote on statehood — an option narrowly defeated in nonbinding referendums he oversaw in 1993 and 1998.

The Caribbean island has been a U.S. territory since 1898. The island was given limited autonomy in 1952. Puerto Ricans generally pay no federal income taxes but have no vote in Congress and pay substantial local taxes.

In another American territory, the nearby U.S. Virgin Islands, the nonvoting delegate to Congress, Democrat Donna M. Christensen, faced challengers Krim Ballentine of the Republican Party and independent Warren Mosler.