United Auto Workers President Douglas A. Fraser yesterday formally endorsed Sen. Edward M. Kennedy's (D-Mass.) bid for the presidental nomination, and the White House reacted with indifference.

Fraser's endorsement was seen as an effort to boost Kennedy's chances in the Jan. 21 Iowa caucuses but a top political aide to President Carter predicted that the president would still beat Kennedy in Iowa -- and with the help of rank-and-file auto workers there.

"It wasn't exactly a shock and it's not nearly as bad for us as some people might think," said the aide, who would speak only on background.

"Our polls show us doing well among the auto workers in Iowa," he added. "In fact, we might even pull a majority of the state's UAW people. To put it simply, I would not swap our position in the labor movement with Kennedy's."

UWA spokesmen, while conceding that Kennedy seems headed for defeat in Iowa next week, laughed at the Carter aid's contention that the majority of that state's 50,000 UWA members would support the president.

"Anybody can claim anything right now. . . But it just defies reality to claim, or even suggest that the UWA membership in Iowa supports Carter," a union spokesman said.

Fraser, whose 14-million-member union played an important role in helping Carter make it to the White House in 1976, emphasized that his Kennedy endorsement was personal.

"I want to disabuse anyone of the notions that I think our members are going to march in lockstep with me" in backing Kennedy, he said yesterday at a Washington Press Club news conferece. "We have a democratic union . . . Our members are independent thinkers," he said.

One hundred eithty UAW members, in town for union's communtiy Action Program conference went to the White House Monday night to express their support for Carter.

"Democracy in our union isn't so fragle that it can't stand a little debate," Fraser said, acknowledging those differeces.

Fraser said he is supporting Kennedy because of what he called the senator's 17-year record in fighting for civil and economic rights, and because, he said, Kennedy has the ability "to turn good ideas into legislation."

"His record and his positons on the issues reflect more closely the Democratic Party platform. . . than those of any othe candidate," Fraser said.

He accused Carter of betraying the party resolutions adopted in 1976 -- of failing to carry through on social aid programs, and of "capitulating to Congress" on energy legislation and labor law reform.

Kennedy, in a speech yesterday morning to UAW conference delegates, several hours before the Fraser announcement, made similar allegations against the Carter administration.

Carter has failed to address the problems of inflation, high intrest rates and unemployment, Kennedy said. The administration has also failed to keep its promises to aid the elderly, to crack down on domestic oil prices and profits and to provide a meaningful national heath care plan, he said.

Carter, instead, has been "following the age-old pollcies" of past Republican administrations, Kennedy said.

"I say to you that 12 long years of Republican economic policy is enough, and that it's time to put a real Democrat in the White House," Kennedy told his standing, cheering audience.

Fraser said he expects Kennedy to win 40 to 45 percent of the Iowa democratic caucus vote.