As Tom Tauke, the 31-year-old, second-term congressman from Iowa's 2nd District, drove down Rte. 13 Saturday morning to a meeting with constituents in this shopping center of Delaware County, which claims to be the largest hog-producing county in the nation, a brisk wind chased white clouds across a Grant Wood landscape that seemed a picture of serenity.

But it was a mirage.

"There's a feeling of tension and uncertainty in the district," Tauke was telling a visitor. And that is why this Republican, shakily perched in a district that gave Gerald Ford, Jimmy Carter and Ronald Reagan each exactly 49 percent of its votes in 1976 and 1980, is coming back to Washington this week aching for a compromise on the budget.

How typical he may be of the House is uncertain. But Tauke, on his visits at home, heard plenty that encourages him to think the voters will accept pension cutbacks, tax hikes and a slower defense buildup--as he suggests--in hopes of cutting deficits and interest rates.

This part of northeastern Iowa is desperate for relief, and so is the congressman who puts his career on the line 28 weeks from now.

In Cedar Rapids, its largest city, he had just left a meeting with federal workers and retirees, who made barbed comments contrasting President Reagan's "$3 million Caribbean vacation" with the cutbacks in their health insurance.

Cedar Rapids, said a member of Tauke's district office staff, "used to think it was recession-proof. But no more." Layoffs and a slump in retail trade have scared everyone.

The day before, Tauke said, he had met for three hours in Clinton with farmers and their bankers, worried about the prolonged slump in agriculture. "They can defer foreclosure on their loans for a couple years of bad prices," Tauke said, "but the worry now is that the asset base on which the loans were made--the value of the land--is beginning to erode, and that can have a spiraling effect downward."

Still ahead of the congressman, before he returns to Washington this week to confront the question of the 1983 budget, was the most painful meeting of all: with union leaders and management at Dubuque Packing, which announced a week ago it would end operations in October, idling 1,200 employes and taking close to $1 million a year out of city tax revenues.

In a community where January unemployment hit 23 percent, reportedly the highest in the nation, and where further furloughs are scheduled at the John Deere works, already down from 6,000 to 3,000 workers, the packing house shutdown almost sounded a death knell.

On Friday night, in the Dubuque Knights of Columbus hall, Tauke's Democratic challenger, Brent Appel, a lawyer and party activist, kicked off his campaign. The crowd seemed too stunned to cheer.

Mike Blouin, the former Democratic congressman beaten by Tauke in 1978, tried to rally them by telling them what they already knew.

"We are being crushed," he said, "so we must fight back . . . . Brent Appel would not have voted for the most unfair tax bill in American history . . . or for a budget that destroyed vital human service programs while financing the greatest military spending increase in our peacetime history . . . . Brent Appel would have stood up to President Reagan and said no to policies that have cost thousands of jobs here in Dubuque . . . . And his one vote might have made a difference."

Tauke, who upset some staunch conservatives in his party by backing Ford and George Bush over Reagan in 1976 and 1980, supported the Reagan budget and tax cuts in 1981. Now, while not criticizing the president directly, he is moving away.

He is challenging Reagan's insistence on a rapid defense buildup. He voted against the B1 bomber and the MX missile last year (after supporting the latter in his first term) and is sponsoring the "nuclear freeze" resolution in the House. Today, he spoke at a Ground Zero antinuclear rally.

Even here, in a strongly pro-Reagan county, Tauke told some 50 town meeting guests, "We can't solve our defense problems, any more than we could end poverty problems, just by throwing money at them."

Unconsciously echoing a line Democrat Appel had used Friday night in criticizing Reagan's defense budget in Dubuque, Tauke said, "One of the best weapons we could have would be a strong economy."

There was no argument; quite the contrary. As heads nodded in agreement, one elderly man said, "Why not take 3 or 4 percent out of defense and use our food surplus as a weapon overseas--feed people instead of starving or bombing them?"

Testing an even more sensitive nerve, Tauke told both the federal workers and retirees and the largely elderly audience here that their pensions' cost-of-living adjustment (COLA) formulas probably would have to be cut back.

"When I last met with you," Tauke told the federal workers, "I said I would never support a change in the COLA. I cannot make the same commitment today."

In the next 90 minutes, only one person took issue with him, saying it seemed "a little unfair" to change the formula.

"I certainly feel uneasy about it," Tauke said, "but none of us are going to have any security unless we get this economy turned around."

Later, Tauke told a reporter he thought the need for a budget compromise is so critical he would even vote for one that included, not just a COLA adjustment but a deferral of the third-year tax cut, "even though a substantial majority of my voters don't want to give that up yet."

He thinks the budget decision is vital to the economic and political future. "Even though Reagan is perceived as pretty inflexible right now," Tauke said, "I'm sure he could manage to make the Democrats take some of the blame if there's an impasse. But we need a compromise that will send a signal to the financial markets.

"Even with a compromise, the economy here won't recover quickly. But if there's some progress by November, there's enough understanding on the part of the public, and support for what Reagan is trying to do, that the election may be all right. But without a compromise in the next 60 days, I'm afraid interest rates will go up, and that will make it very rough for everyone."