Congress will soon decide what to do, if anything, about the greatest tide of illegal immigrants in history. ''Right now the US Border Patrol is completely overwhelmed and undermanned,'' said Roger Conner, head of the Washington-based Federation for American Immigration Reform, testifying this week before a House appropriations subcommittee.
Alan Nelson, commissioner of the Immigration and Naturalization Service (INS) , told a Senate committee recently that the rate of apprehensions by the Border Patrol is up 30 percent over last year and is the highest in 30 years.
Congress must decide whether to enact the pending Simpson-Mazzoli bill that for the first time would impose sanctions on US employers who knowingly hire illegal aliens. Key elements in the situation: some 10 million unemployed Americans; a Mexican economy in serious trouble; and an expanding population below the border that can't find work.
The point of stress is the US Border Patrol. Working in eight-hour shifts, it can put only 450 men on the 2,000-mile border at any one time. Some compare the present chaotic situation to Prohibition, when the federal government couldn't, or wouldn't, enforce the law.
Mr. Conner called the administration's INS budget request of $547 million for the new year a ''disgrace.'' He said it ''completely discredits the administration's announced commitment to regain control of the nation's borders.'' He wants $813.8 million and 1,517 more personnel on the border.
Congress failed to pass the pending immigration restriction law last year. Some observers believe if the measure isn't passed soon, it will have to wait until after the presidential election next year.
One controversial feature of the pending bill would be to grant amnesty to many aliens now illegally in the US. Many estimates on the number of illegals range from 3 million to 6 million, although former INS commissioner Leonard Chapman in 1976 put the figure at 12 million. Only one out of ''every three or four'' illegals is apprehended, he estimated.
A special report in the April 11 issue of Newsweek magazine describes conditions at a particular border point: ''On a single Sunday last month, the US Border Patrol in one southern California sector captured a record 2,442 illegal immigrants.''
Bad economic conditions in Mexico have led to an increase of the numbers of illegal aliens crossing the border. At the same time, the transport of illegal drugs over the border has stepped up also, with the result that US enforcement personnel in the Southwest are stretched to the limit. The US Drug Enforcement Administration is reported to be ''hopelessly outmanned.'' In one district, for example, the agency has only 34 agents, many fewer than it had 10 years ago.But these agents have to cover the 200 miles of border ranging from Brownsville to Laredo.
Testifying here, Mr. Conner, whose non-profit organization conducts research and analysis on US immigration policy, expressed concern that the Simpson-Mazzoli bill does not provide increased border enforcement.
''For the past 10 years,'' he said, ''every official government report on immigration has agreed on one thing - a blanket amnesty for illegal aliens would be ill-advised until the US regains control of its borders.'' He called the administration's proposals ''too little and too late.''