High US unemployment could scuttle the Reagan administration's plans to push an immigration reform package through -Congress this year.
Congressional staff members explain that congressmen facing elections are in no mood to make what many see as concessions to illegal aliens. As more reports surface showing that this country's 3 million-to-6 million illegal aliens may be taking jobs from American citizens, the administration's sales job gets tougher.
The problem showed up in hearings Jan. 25 before the Senate Judiciary Subcommittee on Immigration and Refugee Policy. State, Justice, and Labor Department officials outlined the case for flexible policies to allow the administration to respond to emergencies such as last year's influx of refugees from Cuba, Haiti, Nicaragua, and El Salvador.
But to critics who demand cutbacks in this country's immigration quotas, ''flexibility'' would open the door to more job losses for American citizens.
''Immigrants can be admitted only at the expense of present residents,'' Environmental Fund board chairman Garrett Hardin told the Senate subcommittee. University of California Professor Hardin warned that allowing a high rate of immigration to continue builds up divisive political forces that threaten democracy.
Of course, not everyone agrees with such views. Nina Solarz, executive director of the Citizens' Committee for Immigration Reform, says this sort of ''backlash'' is natural ''with present economic conditions.'' She warns that passing new legislation now could bring sharp reductions in legal quotas for immigrants and refugees. By waiting for nonelection-year 1983, she says, congressmen ''could take more courageous stands.''
Reaction against immigration reform proposals wasn't triggered by any administration surprises. Government officials at the Senate hearing simply went over points presented last July -- points based on a bipartisan report and on consultations with the Mexican government. Under the administration proposals, concessions would be balanced against new toughness. The measures would include:
* Tight controls to restrict illegal entry from Latin American countries either by land or sea.
* More controls inside the US to apprehend illegal aliens -- and to penalize employers who knowingly hire illegal aliens.
* Legal status for many aliens currently in the country illegally.
* New procedures for more Mexicans to enter the country legally. As part of the plan, the administration would double the yearly quotas for both Mexican and Canadian immigrants from 20,000 to 40,000. Since Canadians are unlikely to fill their full 40,000, any of these unused slots would be added to Mexico's quota.
As long ago as last July, President Reagan stressed the importance he places on immigration reform. Along with tighter controls, he explained that concessions are needed because ''illegal immigrants in considerable numbers have become productive members of our society and are a basic part of our work force.''
Groups on all sides of the immigration question, however, say it is meaningless to propose boosting legal Mexican immigration to 40,000 or even 60, 000 when at least 300,000 Mexicans enter the country illegally every year -- and when 9.5 million Americans are unemployed.