"A diverse campus is good for all students," says Tang.

In New York City, Stanton Shen opposes such admissions policies vehemently. Two years ago, Shen left his hometown in Zhejiang province alone, to enrol in a private high school in New York. His parents spend more than US$20,000 a year on him, hoping a US high-school education will get him closer to a place at a top university in America.

"If I work harder and get better scores than a black student, but he gets the admission and I don't, it'd be really unfair," says the 12th grader, who often studies until midnight and attends prep school at weekends. "I think colleges should only judge students on their merits rather than what they look like," he adds.

The difference of opinion between Tang and Shen is indicative of an ongoing national debate spurred by the court case that took Tang and Sharpton to the Supreme Court steps - Fisher vs the University of Texas. Abigail Fisher, a white student who was denied entry by the university, had sued for discrimination, claiming applications from minority applicants were favoured over those from whites. A lack of transparency in college policies as well as the large degree of discretion allowed to admissions officers mean it is hard to prove how much race counts in the admission or rejection of any one student.

The Supreme Court's decision, which is expected to be issued some time before June, may have a significant impact on college admission policies in the US as well as on the broader implementation of affirmative action, a phrase that first appeared in federal government mandates promoting equal opportunities in the 1960s. It has since become the basis for racially conscious admission policies.

However, unlike blacks and Hispanics, who are obvious beneficiaries of such policies, and whites, who are obvio-usly not, there is no consensus about how Asians fit into the picture. The debate within Asian communities has become vitriolic.

Tang's racial mix may have given him a broader view of the balance of interests but the idea is harder to understand for someone like Shen, who grew up in a largely homogenous society where college admission is based mostly on scores in entrance tests.

Twenty years ago, neither of these attitudes were typical of Asian students in America. Now, a more diverse Asian-American population means the interests of different subgroups often conflict; and a section of the population that not so long ago agreed on the importance of being united is now facing a difficult question: is a unified approach and voice still possible?

"There were Asian descendents in the United States since before it was the United States. But they didn't call themselves Asian Americans until 1982, when Vincent Chin was killed," says Frank Wu, chancellor and dean of the Hastings College of the Law at the University of California, referring to a 27-year-old Chinese American who was beaten to death by a pair of car workers in Detroit who mistook him for Japanese and attacked him because of their anger over that country's car sales in the US.

Chin's death spurred an outcry among Asians in the country. For the first time, Chinese, Japanese, Koreans and many other Asians stood together - and eventually saw the killers brought to justice.

"The Vincent Chin case … made people see that they had to build a coalition. Even if your grandparents and their grandparents were at war in Asia, you are in America and you all look the same," says Wu, who is writing a book about the case and its impact.

Since Chin's death, American-Asian demographics have changed dramatically. Their number has reached 15 million, 5.8 per cent of the entire population of America, compared with a mere 1 per cent in 1965. And with a 46 per cent jump in numbers from 2000 to 2010, Asian Americans now make up the fastest-growing racial group in the country.

The composition of the Asian population has also changed a lot. The refugees and green-card lottery winners from Southeast Asia who came here in the 80s are one part of the population. But among the others are the undocumented Chinese smuggled in from rural areas of Fujian province in the 90s and the nouveau riche from China who got green cards through investing US$500,000 in the country in recent years. Add in Indian software engineers and many other groups and you have a rich tapestry.

"The community has grown so much. It now includes people who are adopted, people with mixed-race background, people who just arrived here and people who are the sixth generation, people who go back and forth between the US and China and people who have never set foot anywhere in Asia," says Wu. "It's unrealistic to hope such a diverse group of people will have the same view."

Complicating matters further, ironically, are the success stories. From basketball star Jeremy Lin to a winner of the reality-television series Yul Kwon; from "tiger mom" Amy Chua to the US Ambassador to China, Gary Locke - Asians seem to be rising in all fields. In academia, Chinese, Koreans and Indians regularly win prestigious national high-school science competitions. They are also better represented in the Ivy League colleges than many other minorities. In its report, titled "The Rise of Asian Americans", the Pew Research Centre designated Asian Americans "the highest-income, best-educated and fastest-growing racial group in the United States."

But this is an incomplete picture.

While the more established subgroups are thriving, smaller groups are still suffering from high poverty and low education. For example, only 26 per cent of adult Vietnamese Americans are college educated compared with 70 per cent of Indians, 53 per cent of Koreans and 51 per cent of Chinese, and more than half the adult Cambodian, Hmong and Laotian Americans don't even have a high-school degree. The average annual income for Japanese and Indians is about US$40,000, compared with US$16,000 for Hmong.

These disparities have further weakened the foundation of the Asian alliance, which, with 45 ethnicities and more than 100 spoken languages, has a fundamental flaw.

"The Asian-American identity is a reactive identity. There is no unified language, culture or religion to tie people together. We formed a pragmatic unity in order to fight for equal rights," says Peter Kwong, professor of Asian-American Studies at City University of New York's Hunter College. In the 80s, the professor participated in protests to stop colleges placing a quota on Asian students to limit their numbers and helped to push the chancellor of the University of California at Berkeley, where Kwong then worked, to publicly apologise for the policy.

"The unity worked in the old days, when Asian Americans were mostly poor and targeted by racial discrimination. But it's never been a strong one. On many issues, we only stood together emotionally but were not indeed 'together'," says Kwong. "Now, open discrimination has subsided and Asian Americans are more and more competitive it is even harder to hold the community together."

Fragmentation can be seen everywhere. For example, in Asian-dominated Flushing, a suburb of Queens, New York City, Chinese and Koreans tend to run separate campaigns in support of their own ethnic candidates in elections. In Chinatown, the question of whether residents have more in common with the high-income Asians living in the financial district or the low-income Hispanics living in the neighbouring Lower Eastside has led to a tough debate - particularly when it comes to redrawing city council districts.

However, nothing has polarised American Asians as much as the affirmative-action issue. This is largely because it is about education, the issue that almost all Asian communities care most about. To some, affirmative action also punishes the traditional Asian hard work ethic.

"Affirmative action used to be a good thing, when minorities didn't have enough resources to help them get into college. But now it is a different time," says Lu Ming Li, the director of the Asian American Coalition for Education, a New York-based organisation that helps mainly Chinese students prepare for the SAT exam - the standardised test needed for admission to college - and for college applications. "Governments allocate so much funding to schools in the minority-dominated neighborhoods. If you still cannot study well, then it might be because you are not working hard enough."

Li, who is from Hong Kong, says that those of her students who get into Ivy League universities tend to sleep for just five or six hours a night and spend almost all of the rest of their time studying. But she also knows the cards are stacked against Chinese students at some Ivy League schools.

"I don't want to name names, but some schools, when they have to choose between a Chinese candidate and a non-Chinese candidate, they are much more likely to choose the latter," says Li, who deters her students from applying to those schools.

Li's suspicions are shared by those Chinese and Indian parents who have filed formal complaints against Princeton and Harvard universities to the Office of Civil Rights of the Department of Education in recent years. And this is also what prompted S.B. Woo and his 80-20 Initiative - an organisation he founded in the 90s to consolidate Asian political influence (by trying to aggregate 80 per cent of their vote) - to launch a legal challenge to race-conscious admissions.

Woo, a former lieutenant governor of Delaware state and a retired professor in physics from the University of Delaware, says his organisation has received many complaints over the years from Asian parents believing their children had failed in their Ivy League applications merely because of their race. But he refused to be guided by anecdotes and kept supporting the race-conscious admissions policy - until he came across two academic papers.

One, conducted by Princeton sociologist Thomas Espenshade, found Asians need much higher SAT scores to get into top schools. And the other, by UCLA law professor Richard Sander, found that students placed in elite schools above their academic level through affirmative action often find it hard to cope, and many don't graduate.

"Before, I thought 'Even if those Asian parents were right, if affirmative action offers chances to under-served black and Hispanic students, it may be worth the sacrifice of some of the better-served Asian students,'" says Woo. "When I looked at the Sander report, I thought, 'How stupid I was. How come I didn't see this?'. I was a professor myself. This solved the moral dilemma faced by 80-20."

In May, 80-20 did a study of its own; 50,000 Asian Americans across the country were surveyed and supported a "race neutral" policy by a ratio of 52 to 1.

The Asian American Legal Defense and Education Fund (AALDEF), on the other hand, quotes research showing that Asians largely support affirmative action. These include voter polls in California and Michigan that found a majority of Asian voters voted against proposals to prohibit public universities from considering race in admission. A multi-city survey of Asian Americans by the Inter-University Consortium for Political and Social Research found that more than 60 per cent of respondents said affirmative action was a good thing. Less than six per cent thought it was a bad thing. A Pew Centre report, meanwhile, found that 61 per cent of Asian Americans think being Asian has no effect on collegiate admissions.

Among supporters on this side are some students and faculty members at the University of Texas at Austin, the school at the eye of the storm. Jennifer Tran is one.

An American-born Vietnamese Chinese, Tran, now in her third year at the school, didn't benefit from her race - she was admitted via the school's merit-based policy, which sees the top-performing 10 per cent of students in Texan high schools being accepted automatically. But, she says, even under policies that take other factors into account, race is just one of many. And admissions decisions are not a zero sum game.

"It's an unhealthy way to look at it, as your pool versus everyone else's pool," says Tran, director of operations of student organisation Asian Desi Pacific Islander American Collective. Still, she says, with more than 100 Asian student organisations on the campus, it is not easy to get a consensus.

"People who don't support tend to be people from higher-income families," says Tran. "It's easy to forget how much help you got to get here."

Both sides challenge the methodologies of the various surveys, especially the ways the questions were laid out. They both claim to represent the majority view.

"I don't think we are divided," says Woo. "The organisations might [be]. But the community is not. Look at the survey, the 50 to 1 ratio means the majority support us."

"I don't think it's quite as divided as the news media wants to make it seem," says Thomas Mariadason, staff attorney of AALDEF's Educational Equity and Youth Rights Project. "If you look at the numbers, the number of organisations that filed amicus [independent opinions filed in court] for affirmative action was so much more than the number that filed amicus against it."

But the fundamental differences between the two sides do make clear the tough choices ahead: should the interests of smaller groups be embraced, or should they be treated like everyone else?

"Let's take Hmong. Their population [in the US] is only 260,000. Yes, their poverty rate is higher than average. But the Hmongs that benefited from affirmative action, I bet you, won't be more than five a year," says Woo. (Some colleges allow applicants to tick a sub-racial group such as "Hmong", others would count them as "Asian").

"If you pay attention to [the interests of] the smallest minority and adjust the policy [against the interest of] the majority, it's dumbass," he adds. "No government makes decisions that way. If you want to serve special-interest groups, that's fine. But if you want to serve Asian Americans in general, you cannot afford to take such positions."

The response from the other side of the debate is equally heated.

"The majority certainly have much more influence. But American democracy has been structured to also protect the rights of the minority. That's why Asian Americans have been able to fight for our rights," says Mariadason. "There is certainly a lot of value to have the unified voice. But it shouldn't come at the expense of other voices that are trying to get into the discussion.

"It's very important to provide an arena for the emerging Asian communities to have their voices."

"The community is more complicated and better organised. It's impossible to speak for an entire racial group. But I am not troubled by that at all," says Wu. "If we spoke in the same voice, it would be absurd. It would make the stereotype true.

"I think it's good that Asian Americans show robust disagreement. The community is mature enough to have different views."