The House of Representatives vote offering Puerto Rico a path to statehood may have taken the nation by surprise, but politicians on this Caribbean island have been planning the moment for years.

A well-orchestrated campaign has poured millions of dollars into lobbying firms, advertisements in Washington newspapers and campaign donations. Every week for more than a year, the island's legislature has sent delegations to Capitol Hill.Gov. Pedro Rossello's pro-statehood party has been cementing its importance by taking key posts in national civic groups. Proponents quietly collected the endorsements of President Clinton, House Speaker Newt Gingrich and key lawmakers.

On Wednesday, the lobbying efforts paid off: the House voted 209-208 to hold a special referendum on Puerto Rico's status. If approved by the Senate, the referendum would give Puerto Ricans three choices: continued commonwealth status, statehood or independence.

Local politicians long have hoped to resolve Puerto Rico's tangled century-old relationship with the United States.

Although they are U.S. citizens, Puerto Ricans have no vote in Congress and cannot vote for president. They do not pay federal taxes but receive benefits, including welfare and housing funds. They can be drafted into the U.S. military but field their own Olympic team.

Earlier statehood efforts have failed - even one in 1990 backed by President Bush.

For years before the House vote, Rossello's pro-statehood New Progressive Party has been gaining stature in national political organizations. A Notre Dame-educated pediatrician, Rossello is now chairman of the Southern Governors Association, head of the Democratic Governors Association and president of the Council of State Governments.

Kenneth McClintock, a pro-statehood island senator, is chairman of the legislative wing of the Council of State Governments, in which other Puerto Ricans hold key positions.

Commonwealth legislator Carlos Lopez Nieves became a vice president of the League of United Latin American Citizens after he built the Puerto Rican chapter from three local councils into a 150-council powerhouse. The league endorses a plebiscite.

Clinton is also an ally, affirming his support in a letter read to the House on Wednesday.

The Capitol Hill newspaper Roll Call reported Thursday that pro-statehood advocates paid Washington lobbying firms more than $2.3 million in the first half of 1997, while those opposed spent $400,000.

Statehooders have also proved skillful fund-raisers for the bill's allies.

Puerto Ricans donated more than $2.8 million to races in which they could not vote. They gave $280,000 to three Kennedy family candidates in the 1996 elections. Clinton received $1 million for his re-election campaign.