President Reagan's latest pitch for his economic program lost a lot of its zip as it sailed across the airwaves to this hard-hit corner of the country.

Julie Williamson, who runs the Portland office of Rep. Les AuCoin, a liberal Democrat, said Friday that she and her colleagues "were dreading coming in today." After the president asked voters on his Thursday night television broadcast "to make your voice heard," she presumed they would be deluged with calls demanding that AuCoin back the president's budget.

"Last year, when he went on TV, we got about a thousand calls," Williamson said, "and 90 percent of them said, 'help the president.' Some of them were really vicious. People were saying that the Democrats had caused all these problems and they better not block Reagan. One man threatened to give Les' opponent $1,000 that day if Les didn't vote with the president.

"We were in tears by the end of the day," Williamson recalled, "so two of our women brought in coffee cake today, just to keep morale up. But it wasn't like last year at all. This time, we've only had about 30 calls, and they are running 50-50 between those who say get off your butt and support Reagan and those saying Les is right to oppose him and insist on less defense spending and getting the deficit down."

The offices of Oregon's two Republican senators reported a similar shift from last year. Tom Imerson, an aide to Sen. Mark O. Hatfield, said the count was 74 to 47 in favor of Reagan, and Elaine Franklin, an aide to Sen. Bob Packwood, said their count was 55 to 42 for Reagan. In both offices the volume was smaller and the support lower than last year. Franklin said, "I'd say last year was about 30 percent more favorable."

What has changed, they say, is not Reagan's rhetoric but people's mood. "There was a lot more optimism last year," Franklin said. Now, Oregon and Washington have double-digit unemployment and their major industries--forestry, housing, construction and aircraft--are crippled by high interest rates, which are linked to the government's huge projected budget deficits.

In Seattle Thursday evening, civic leaders from government, business, labor and community organizations interrupted a seminar on Reagan's federalism initiative to watch the president's speech.

When Reagan closed by telling the viewers, "you did it before, and you can do it again," there was derisive laughter from some. "Yeah, we did it to ourselves before," one man commented, "and we'd be bigger fools to do it again."

Later, a seminar leader said "most of the business people here don't blame Reagan for the interest rates. They were high before he came to office. But they think his policies have exacerbated the problem, instead of relieving it."

A sense that Reagan was sidestepping his own responsibility was apparently one reason for the weakness of the response out here.

The Portland Oregonian published an analysis of the speech by Newhouse Newspapers' Loye Miller, which began, "President Reagan attacked his own budget Thursday night as if it were a hostile invader from outer space." This morning, the paper followed up with an editorial saying, "The president's effort to pass the buck Wednesday to Democrats in a ludicrous prime time speech was a White House comedy monologue."

When Republican national chairman Richard Richards told the Portland City Club, whose members are the city's political and business establishment, Friday noon that the Democratic speaker of the House "is the fly in the ointment of the budget negotiating process," he evoked a wave of skeptical questions.

Reagan has strong defenders, still. Among them is Bill Mashofsky, a retired vice president of Georgia-Pacific who is the Republican challenger for AuCoin's seat.

Mashofsky said he was campaigning on Reagan's theme that the deficits were the result of years of uncontrolled Democratic spending, but he conceded that "the psychological impact of Reagan's coming in with big deficits in his own budget has been really damaging."

Like almost all the other Republicans from this region, Mashofsky is calling for cutbacks in Reagan's defense budget, but he still supports the full three-year tax cut. To others, however, tax-cutting in Washington is beginning to look simply like an exercise in tax-shifting.

Today, Washington state reimposed a sales tax on food that goes up as high as 6 1/2 percent in cities like Seattle. The voters exempted food by referendum several years ago, but the legislature reimposed the tax as an emergency measure this year, even though the vote was politically risky and repeal is regarded as certain when another referendum reaches the ballot in November.

"We needed the money desperately, even for just a few months," one legislator said.

Here in Oregon, Republican Gov. Victor Atiyeh said he did not see Reagan's speech because he was at a fund-raising reception for his re-election campaign. But he said he asked a guest at the reception what the president had said and got this answer: "He threw a bunch of numbers around that I couldn't understand, and then he said he was for a balanced budget."