Pimlico Race Track owner Nathan I. Cohen called W. Dale Hess, one of Gov. Marvin Mandel's closest political allies, for help in 1972 when a state racing commissioner objected to a provision of a racing law Mandel favored. Cohen testified today at the corruption trial of Mandel, Hess and four others.

Although Hess had concealed his identity as an owner of the rundown Marlboro Race Track, he had been taking an active hand in behind-the-scenes maneuvering regarding proposed legislation affecting the track, Cohen testified.

Cohen testified he called Hess because of Hess' known political clout due to his close association with Mandel. The call was made on March 3, 1972, when the late commissioner Samuel Stofberg objected to an unidentified section of the proposed 1972 Race track consolidation bill.

Moments after Cohen called Hess, Stofberg himself received a telephone call that he later said was from Hess, Cohen testified. After the phone call, Stofberg dropped his opposition to the racetrack bill provision and also called Cohen "an S.O.B." for having called Hess, he said.

The Stofberg incident illustrates the type of connection the prosecution is trying to make between the defendants in the second bribery and corruption trial of Mandel. Hess, Irvin Kovens, Harry W. Rodgers, William A. Rodgers, and Ernest Cory Jr.

Mandel is accused of accepting bribes, clothing, and other favors from his codefendants in exchange for securing racetrack legislation that would have created windfall profits for each of them, the government has claimed.

So far, there has been no direct testimony that Mandel knew that his friends had secretly purchased the rundown facility. The first corruption trial ended in a mistrial after jurors learned of two attempts at jury tampering late last year.

The jury also heard from former State Sen. James T. McAuliffe (D-Montgomery County), who testified that he would have liked to have known of Mandel's business dealings with the other defendants regarding the racetrack issue because "the issue of public confidence in government" demanded it.