THE FACTS OF MIMMS (1977), WERE UNDISPUTED. TWO POLICE OFFICERS STOPPED AN AUTOMOBILE TO ISSUE A TRAFFIC SUMMONS. ONE OF THE OFFICERS ORDERED THE DRIVER OUT OF THE CAR. AFTER HE HAD COMPLIED, THE OFFICER NOTED A BULGE UNDER MIMMS' COAT. THE OFFICER, BELIEVING MIMMS TO BE ARMED, FRISKED HIM AND DISCOVERED A GUN AND FIVE ROUNDS OF AMMUNITION. A FOUR TO THREE MAJORITY OF THE PENNSYLVANIA SUPREME COURT HELD THAT UNDER THE FOURTH AMENDMENT, THE POLICE COULD NOT ROUTINELY ORDER MOTORISTS WHO HAD BEEN STOPPED FOR TRAFFIC OFFENSES TO LEAVE THEIR CARS. THE U.S. SUPREME COURT SUMMARILY REVERSED THE DECISION OF THE PENNSYLVANIA SUPREME COURT AND HELD THAT A POLICE OFFICER WHO HAS PULLED OVER A VEHICLE FOR A TRAFFIC OFFENSE HAS A GENERAL RIGHT, CONSISTENT WITH THE FOURTH AMENDMENT, TO ORDER THE DRIVER OUT OF THE VEHICLE. THE DECISION IS HIGHLY SIGNIFICANT BECAUSE IT MANIFESTS TWO CLOSELY RELATED DEVELOPMENTS IN JUDICIAL EVALUATION OF INVESTIGATIVE POLICE CONFRONTATIONS. THE FIRST IS THE WILLINGNESS TO BASE CERTAIN FOURTH AMENDMENT DECISIONS ON A COURT'S KNOWLEDGE OR IMPRESSION OF THE GENERAL CONDITIONS SURROUNDING THE POLICE ACTIVITY RATHER THAN ON THE FACTS OF THE PARTICULAR CASE. THE SECOND IS THE JUDICIAL APPROVAL OF MINIMAL POLICE INSTRUSIONS IN SITUATIONS WHERE THE FACTS WOULD NOT SUPPORT A FULL STOP AND FRISK. IN ADDITION, THE CASE REFLECTS THE COURT'S APPARENT DESIRE TO LIMIT FEDERAL JUDICIAL INVOLVEMENT IN CERTAIN KINDS OF POLICE ACTIVITY THAT WOULD COME UNDER THE FOURTH AMENDMENT. THIS DECISION MAY BE VIEWED AS AN EXTENSION OF THE COURT'S HOLDING IN TERRY V. OHIO (1968), WHICH BROUGHT POLICE 'STOP AND FRISK' ACTIVITIES UNDER THE PROTECTION OF THE FOURTH AMENDMENT AND FORMULATED NEW CONCEPTS OF REASONABLENESS FOR EVALUATING THESE ACTIVITIES. IT IS DIFFICULT TO DETERMINE THE IMPACT OF MIMMS BUT IT COULD BE USED TO LOWER FOURTH AMENDMENT SAFEGUARDS AGAINST INTRUSIVE POLICE PRACTICES. FOOTNOTES ARE INCLUDED IN THE ARTICLE. (LWM)