AS MILLIONS OF ILLEGAL ALIENS FLOOD INTO THE UNITED STATES, CHARGES ABOUND THAT THESE 'INVADERS' MILK WELFARE, TAKE JOBS FROM CITIZENS, AND TURN TO CRIME. DATA FROM FEDERAL AND STATE OFFICIALS, SOCIAL SCIENTISTS INVOLVED IN RESEARCH, AND REPRESENTATIVES OF IMMIGRANT GROUPS CHALLENGE MANY OF THESE IDEAS, BUT ALL AGREE THAT SOMETHING MUST BE DONE. MOST EXPERTS SUGGEST THAT A COMBINATION OF JOB CONTROL, BETTER SCREENING OF APPLICANTS FOR TOURIST AND STUDENT VISAS, AND INCREASED BORDER PATROLS COULD DRASTICALLY REDUCE THE NUMBER OF NEW ILLEGAL ALIENS. BUT THEY ALSO AGREE THAT THE FLOW CANNOT BE STOPPED ENTIRELY....ELW