SPRINGFIELD, June 10--The Democratic pre-primary convention limped to a close here early this morning, after delegates to the wild and colorful three-day show endorsed Harvard graduates for the two top spots on the ticket.

Edward M. "Ted" Kennedy '54 and his precision-perfect organization swept the endorsement for U.S. Senator from Massachusetts Attorney-General Edward J. McCormack Jr., but McCormack, charging "White House pressure" and "Federal arm-twisting," withdrew halfway through the first ballot and vowed to "take my case to the people" in the September primaries.

After the much-heralded Kennedy-McCormack clash on Friday night, Saturday's struggle for the gubernatorial endorsement could easily have been an anti-climax.

But Endicott "Chub" Peabody '42 and State Lt. Governor Edward F. McLaughlin Jr. battled desperately through ten tense hours of balloting, and not until about 7:30 p.m. yesterday evening did Peabody triumphantly make his way to the Convention platform to accept the endorsement.

McLaughlin, tired and bitterly disappointed, conceded the election after the second ballot. He was about 100 votes behind Peabody. McLaughlin is not expected to enter the Democratic primary, and Peabody will thus face only token opposition from State Registrar Clement A. Riley who trailed far behind in yesterday's voting.

Peabody has served as a member of the Governor's Executive Council and was an All-American guard during football days at the College. He has promised "a return to decent government in the Commonwealth" and billed himself as "the only Democrat who can beat (Gov. John A.) Volpe in November." It was Peabody's first convention victory in three tries.

The Convention also endorsed State Rep. Francis X. Bellotti of Quincy for Lt. Governor and Rep. James R. Lawton of Brockton for Attorney-General. All Convention endorsements may, however, be challenged in the September primary, and other clashes besides the bitter Kennedy-McCormack struggle are expected to continue through the summer.

Massachusetts Democratic conventions are traditionally three-ring circuses, and the 1962 edition was no exception, despite the intense national attention centered on the main bout between President Kennedy's youngest brother and Speaker McCormack's favorite nephew.

Even before the first session was gaveled to order by State Democratic Chairman John M. "Pat" Lynch, a brawl among members of the Credentials Committee had to be stopped by Springfield police. And there was action aplenty outside the Convention hall. On Thursday morning McCormack called a press conference at the Sheraton-Kimball Hotel and charged Kennedy with lying about the number of times he has voted since turning 21.

McCormack produced voting records to prove that Kennedy had voted in only two elections in the last nine years. Kennedy did not vote in the Presidential election of 1956, and, asserted McCormack, "a man who does not consider the President important is not a responsible citizen."

McCormack also claimed possession of documents to prove illegal "White House pressure" on convention delegates but declined to produce them. "Such action might hurt the Democrats in the 1964 Presidential elections and cause a national issue to arise in a local contest," McCormack asserted.

"If Teddy gets elected," McCormack said, "the Kennedy dynasty will be the greatest national domestic issue in 1964 for the Republicans. I'm doing my patriotic duty and a service to the President" by trying to beat him.

One Kennedy supporter said the candidate "is crazy if he answers the charges," but Thursday afternoon Kennedy denied all the allegations and challenged McCormack to produce evidence.

"These charges insult the integrity and decency of the delegates," Kennedy asserted, asking the Attorney General to "try cases in the courts, not in the newspapers."

Kennedy also noted several improvements he hopes to make in the Democratic Party organization: a full-time organization director, more active local committees, and a broad base for party finance. Kennedy said that he had conferred on many of the ideas with Samuel H. Beer, professor of Government.