The poor showing of the G.O.P. among Latino voters in 2012 is the political subtext for much of the immigration debate in Congress this week. But Republicans also need to consider the impact of their words and deeds on the nation’ s fastest growing demographic: Asian-American voters, who are at least as invested in the immigration issue as Latinos.

As recently as the early 1990s, many Republicans considered the Asian-American population to be a “natural constituency” for their party, given the traditionalist social views, entrepreneurial orientation, and relatively high socioeconomic status of many Asian Americans. At the time, this was borne out by vote tallies: in the three-way presidential race of 1992, George H.W. Bush received 38% of the national electorate but 55% of the Asian-American vote.

By 2012, however, Mitt Romney drew the support of just 28% of Asian Americans. In every category of age, citizenship, ethnicity, and nativity, Asian Americans (here taken to include people of Pacific Islander ancestry) now report a preference for the Democrats.

The two-decade long collapse in Republican support among Asian-American voters towards the Democrats has been ascribed to multiple causes, including the end of the Cold War, changes in the demographic composition of the Asian-American population, and broader shifts towards the Democratic party in the heavily-Asian West Coast states and Hawaii, where nearly half of Asian Americans reside. But the politics of immigration has also been key.

The shift of Asian-American allegiances is often traced back to Republican Pete Wilson’s harshly anti-immigrant campaign for governor in 1994. That was also the year of the infamous Proposition 187 that sought to cut off essentially all state government services to undocumented immigrants and their children. The ensuing backlash accelerated the collapse of the G.O.P. in California, which had been the party of both Nixon and of Reagan.

The story of Prop 187, and immigration in general, is usually seen through the lens of California’s huge Latino population. But the clout of the Asian-American immigrant population will be increasingly hard to discount. Between 2000 and 2010, people of Asian ancestry were the fastest-growing ethnoracial group, increasing by 46% — including an increase in every state of the union. Since 2009, immigration from Asian countries has outstripped that from Latin American countries.

Nearly three-quarters of Asian Americans were born abroad. As first-generation Americans, they remain very close to the immigration experience, and are likely to be affronted by rhetoric and policies that are harshly or indiscriminately anti-immigrant . A survey by the Asian-American Legal Defense and Education Fund (AALDEF) found that 65% of Asian American voters in 2012 (including a majority of registered Republicans) supported comprehensive immigration reform, including a path to citizenship for undocumented people.

The heavy concentration of Asian Americans in such “deep blue” states as Hawaii, California, Washington, New Jersey, and New York may at first glance diminish the G.O.P.’s incentive to focus on Asian-American concerns. But the Asian American population grew in every state of the union between 2000 and 2010. At about 18 million people, or 5.6 percent of the population, Asian Americans nationwide are now nearly half as numerous as African Americans.

In 2012, not only did Asian Americans come out in full force for the Democrats, but voter turnout also increased by 50%. Granted, this was still only from 2% of the electorate to 3%. But that percentage will only increase as more and more become eligible for naturalization, acculturate to the U.S., or reach voting age. Comparatively well-off and well -educated, Asian Americans are precisely the kinds of voters who are most likely, over the long run, to show up at the voting booth.

Not coincidentally, Asian Americans also have increasing influence in the political sphere. The number of Asian American candidates for the House tripled between 2010 and 2012, and Congress now includes an all-time high contingent of 11 Asian Americans (all Democrats). The rate of increase is stunning — of all the Asian Americans ever elected to the House, almost half have been seated since 2005.

If Republicans are serious about being more than a “rump party” of disaffected conservative whites, or hope to lure in at least a few more voters of color, the Asian-American population has become too big to ignore. And for this population of immigrants, the next steps taken by the G.O.P. could shape opinions for a decade to come.

Raymond A. Smith

Raymond A. Smith a Senior Fellow at the Progressive Policy Institute, teaches political science at Columbia and NYU and is an investigator in the Division of Gender, Sexuality, and Health at the Columbia University Medical Center. He is the author of Importing Democracy: Ideas from Around the World to Reform and Revitalize American Politics and Government and editor of The Politics of Sexuality.