Joy Bruce and Winnie Tang spend their nights laboring like college students cramming for finals -- organizing meetings, making phone calls and promoting events -- just to convince South Floridians that they exist.

Bruce presides over NANAY Inc., the first South Florida community center founded by Asian Americans, when she's not on the job as a neuropathologist. Tang works with more than 20 Asian-American organizations when she's not at her 9-to-5 job as an administrative assistant.

Bruce, 54, of North Bay Village, and Tang, 41, of Kendall, personify the rise in Asian-American civic involvement in South Florida, a trend that is especially celebrated throughout May, Asian Pacific American Heritage Month.

''My friends tell me I can't get married or I wouldn't be able to keep doing all this for the Asian-American community,'' Tang said.

South Florida's Asian population has increased 16-fold in the past three decades, from about 4,200 in Miami-Dade and Broward counties in 1970 to nearly 70,000 in 2000, according to the U.S. Census Bureau. They compose about 2 percent of South Florida's populace.

Nationwide, Asians constitute one of the fastest-growing minorities, rising from 6.9 million people in 1990 to 10.2 million in 2000. In New York state and California, traditional points of entry for Asian Americans, they make up more than 10 percent of the population.

And yet some Asian Americans in South Florida say they feel invisible.

''All the time, the media and politicians talk about blacks, whites and Hispanics, and we are ignored,'' said Piyush Agrawal, 65, of Weston, chairman of the Asian American Foundation of South Florida.

In a sense they have been all but invisible, politically. South Florida has seen very few Asian-American candidates for elective office.

But they are becoming more of a social and cultural force. In recent years, dozens of community organizations run by Asian Americans have sprung up in South Florida. And their influence reaches beyond food and festivals.

The Contemporary Chinese School of South Florida, a group of nonprofit centers in Hialeah, Davie and west Boynton Beach that teach Mandarin to kids of all ethnicities, has gone from 30 students to 200 students in the past seven years, said founder Matthew He, 41, of Plantation.

When NANAY -- the National Alliance to Nurture the Aged and the Youth -- got a building three years ago at 659 NE 125th St. in North Miami, the nonprofit center served six senior citizens, Bruce said. Now NANAY caters to 200 seniors, who vary in ethnicity from French to Filipino and play mah-jongg and bingo side by side.

South Florida's chapter of the Organization of Chinese Americans quintupled its membership from 25 to 125 since Tang took over as president two years ago.

The Japan American Society of South Florida, which promotes friendship between the United States and Japan, maintains about 80 members with younger people regularly joining, said James Mihori, 68, of Delray Beach.

This civic boom among Asian Americans could lead to more political involvement, said Marcia Silver, 50, of Hollywood, a Nova Southeastern University professor.

Mariza deGuzman Cobb, 36, of Hollywood, is evidence of this change. She is running for Broward's 17th Circuit Court in the Sept. 10 primary.

''Asians in general don't feel as connected with the political system,'' said deGuzman Cobb, who says she is the only Asian American currently running for a political office in the tri-county area.

In the 1970s, state Sen. Eddie Gong and Judge Dominic Koo, both from Miami-Dade, blazed trails as Asian-American elected officials, said Jack Curtiss, 58, of Cooper City, editor of International Asian American, a 15,000-circulation newspaper published monthly. In 1992, another Asian American, Mimi McAndrews of Palm Beach, was elected to the state House. She lost her reelection campaign in 1994, Curtiss said.

The candidacy of deGuzman Cobb is not the only sign that Asian Americans -- especially younger generations -- are becoming more involved.

A few weeks ago, a protest by college students nationwide persuaded retailing giant Abercrombie & Fitch to yank from its 311 stores a line of T-shirts with images and slogans many said were derogatory toward Asians.

Meanwhile, the University of Miami's Asian American Students Association is vying for its own office so it can address such issues as a possible Asian-American studies minor, said recent graduate and former AASA treasurer Rudy Lue Yen, 23, of Miami.

The next 25 years will bring a more viable Asian-American political presence in South Florida, said Mohammad Shakir, director of the Miami-Dade Asian Advisory Board. He points to the Asian American Alliance, founded in 2000 to urge Asian communities to support candidates and register voters.

As Asian Americans in South Florida mobilize, they should look toward the political influence of such minority groups as Hispanics, said Frank Wu, author of Yellow: Race in America Beyond Black and White and a law professor at Howard University.

''You have to keep trying,'' Wu said. It's not just a positive for Asian Americans but empowers the entire community when everyone can participate as equals.''