A PRECISE AND grotesque demonstration of the flaws in the administration's sweep-'em-up, boot-'em-out campaign against Iranian students is provided by the case of its first local victim, Mohammed Hemmatipour. An apparently nonpolitical person who at great personal and family cost has studied here for four years, he was stopped for jaywalking on Connecticut Avenue. "Are you Iranian?" the officers asked, eyeing his dark complexion and thick beard.. Taking him in to the precinct station, they were roundly congratulated for arresting an Iranian. When it turned out that Mr. Hemmatipour's student visa had expired, making him deportable, one officer shouted, "Give me five!" Mr. Hemmatipour, 15 months short of a degree in respiratory therapy, contends that his new visa, with a new and early expiration date he had failed to notice, was lost in the laundry last June.

Could there be any policy more calculated to bring out the worst in Americans and to wreak harm on hapless individuals than the dragnet authorized by President Carter in partial response to the kidnapping of American diplomats in Tehran? Setting out in high dudgeon to screen the visas of just one group of foreigners was bound to produce the offensive ethnic scenario enacted on Connecticut Avenue. Such is the disarray of immigration records and the variety of foreign-student situations, moreover, that any raw comb through the Iranian community was certain to come up with any number of people as patently unsuited for deportation as Mr. Hemmatipour.

Perhaps a quarter or more of the quarter-million-plus foreign students in the United States are Iranians. Most came to participate in their country's modernization, which was then being championed by the shah and which will surely resume someday. An uncounted number of the Iranians, as of all foreign students, do not have their papers in order. They have some responsibility for this, but so does the United States government -- for the notorious inefficiency and confusion of its procedures controlling foreign students.

To send policemen out in the street to look for swarthy people whose papers are not in order -- when the students apprehended may have no feeling for the Iranian revolution, when they have broken no other law, when their main purpose is to complete their education and return to help their homeland -- is a travesty of the American way. It smacks of Ayatollah Khomeini.