Daniel Yankelovich, pollster for the New York Times, yesterday said that the recent boost in Americans' confidence in President Nixon is due to a belief that he has eliminated the danger of the Vietnam war.

Speaking before an audience of 150 at the Business School. Yankelovich said that Nixon's 28 per cent lead over McGovern can be explained by the relatively calm aftermath of last May's mining of Haiphong Harbor. Since no nuclear confrontation occurred as a result of the mining. Yankelovich said Nixon had effectively diffused the danger of the war by isolating it--by divorcing it from the relations with China and Russia.

"The reception of Nixon (for the summit talks) resulted in a psychological climate as if the war had ended," Yankelovich continued.

The polister said that public opinion polls will produce a new kind of bandwagon momentum in the November election.

"Since 1952 at least 75 per cent of registered Democrats have voted for the Democratic candidate," he said. "This year 43 per cent of the Democrats plan to vote for Nixon, many of whom have never voted Republican. The polls say everybody is switching, thus lessening the Democrats' guilt in doing so," he explained.

Yankelovich said he views the 1972 campaign as "peculiar" because Nixon's "vulnerability" on specific campaign issues does not appear to change voter opinion.

"In a normal campaign, the Watergate episode would make a difference, but not now," he said. "What mystifies me is the anger about McGovern and the forgiveness of veteran Nixon-haters."

Yankelovich said he has seen a trend towards conservation in the last year--conservatives now outnumber liberals by more than two-to-one.

This, combined with the switchover of an estimated 14 per cent of Wallace voters to Nixon has formed a hard core of support that will hurt McGovern's chances. Yankelovich said