The national GOP will stage its first-ever presidential convention in Madison Square Garden in August 2004, marking a daring incursion by Republicans into a city where Democrats still outnumber them 5 to 1.

At least 35,000 Republicans - plus 15,000 reporters - are expected to converge on Madison Square Garden for the four-day event, which City Hall estimated will spin off $150 million to $200 million in hotel bookings, restaurant tabs and other economic activity.

The announcement came after the Republican National Committee's Site Selection Committee voted unanimously to back New York, which edged out Tampa/St. Petersburg, Fla., and New Orleans.

The full RNC must still vote on the recommendation this month, but insiders said the deal is as good as sealed. Party officials believe that the city - with its diversity and its resilience after Sept. 11 - can provide a unique backdrop for President Bush, who has made battling terrorism a centerpiece of his first term.

The selection will come at a price. The event's budget is estimated at $80 million -- $53 million of which Bloomberg has committed to raise privately. The other $27 million will be spent by the city for police, sanitation and other costs.

The deal includes a temporary pedestrian bridge that will span Eighth Ave. to connect Madison Square Garden to the Farley Post Office Building. Some 330,000 square feet of the building will house the convention's media center.

The city's selection comes after six months of lobbying by ayor Bloomberg and special adviser Kevin Sheekey, who will remain in charge of convention planning. Bloomberg secured the support of the city's unions, which promised not to strike during the convention, and hoteliers, which have guaranteed some 22,000 rooms at a modest $156 a night.

"We never made an emotional argument that they should come to New York because of 9/11," Sheekey said. "That may have factored into their decisions, but we focused on giving them the best deal we could."