President Carter made his first appearance of the Pennsylvania primary campaign today in a visit to the East Room of the White House, and over at Lapko's Bar and Grill, the workers just off the 3 o'clock shift at the steel mill didn't much care.

"The economy . . . has slowed down . . . probably . . . in a recession." The president was speaking from over in the corner in the bar, his face filling the color television screen as he launched into an opening news conference statement that was both a crisis report to the nation and a campaign defense of his record.

". . . Recession . . . will be mild, short . . . deeply concerned [about auto plant closings and housing start decreases] . . . know the pain and heartache."

Linda Ezerosky paused to observe: "Oh, yeah -- he knows the pain. He's got things screwed up enough as it is. I'm for Kennedy, so I know all I need to know."

And then the woman, who is an apprentice on open hearth No. 5 over at the Homestead Steel Mill, turned back to the business at hand -- sliding a metal puck down a pinball-like bowling alley, leaving herself a nasty seven-ten split.

As a crisis report to the nation, Carter's news conference was serving its purpose.

But as a campaign appearance, the event was not all Carter might have hoped it would be, at least not in the mostly Roman Catholic, mostly ethnic, entirely blue-collar neighberhood of Lapko's Bar, over on Kenneywood Street in Homestead, just outside of Pittsburgh.

The president was having trouble making himself heard over the ping-and-ding of the pinball machine and the raucus conversation of the men in the back room, who were in the process of building an impressive collection of empty beer bottles.

The president was telling the folks at Lapko's about the prospects of new jobs, and his message was filled with hope.

"Acchhh! That Carter is all obsessed with himself," says Stuart Karan, a machinist at the steel mill. "Carter has got more B.S. than Carter has little liver pills -- get it?"

At the bar, Mary Mamaeff is trying to block out the ping-ding of the pinball and the din of the back room to listen to the president.

"Carter's pretty good," she says. "He's trying -- look at his face, and you can tell it. He's doing his job pretty good. But a half an hour ago, you know what happened to me? Teddy Kennedy shook my hand -- me, just a little worker in Homestead, and he shook my hand. I'm for him. Carter could have come here, too, but he won't."

In an unscientific but saturation sampling of the men and women in Lapko's, the opinions seemed to range from Kennedy-for-president to indifference.

That is a problem the president is starting to face here increasingly -- the candidate in absentia. His wife had also just toured a nearby steel mill, and his vice president had made more appearances here this month than the Pittsburgh Pirates. But in a campaign that is drawing close in the polls, the Carter surrogates may not be enough to allay the concerns of voters, the way they succeeded in Iowa, and New Hampshire and Florida and Illinois.

Some Carter campaign advisers have privately urged the president to do some moderate indirect campaigning such as holding "town meetings," but not necessarily in primary states, as a way of getting around his commitment not to campaign while the hostages are being held in Iran. Since Carter showed no inclination to do that, others have urged that presidential news conferences and other public communication forms serve as substitutes.

In his news conference, the president discounted any tie between the interim event and the Pennsylvania primary. Any date since January would have been just before or just after one of the 35 primaries scheduled for this year, he said.

But over at the union hall of Steel Workers Local 1397, Edward M. Kennedy took time out from his campaigning to view Carter's news conference, and then he held one of his own. Kennedy made it clear that he felt the president's news conference was just about as political as his own. Asked about Carter's plans for the economy, he said:

"I call these Band-Aid solutions to the major rupture in our economy . . . brought about by failed and flawed policies . . . They will give little comfort to the workers and their families.

"I think if the president traveled to Pennsylvania and talked to the workers . . . he would feel less sure that the types of Band-Aid solutions he offered would be successful . . . I think he was trying to put a good face on a very bad situation."

With the Pennsylvania campaign apparently growing tighter, after Carter held a big lead just a few weeks ago, the election may turn on the question of how the blue-collar ethnic Catholics of the state will vote.

These were Kennedy people back when Kennedy's brothers were running for president, but they have only been his people on a few occasions this year. They supported Kennedy in Connecticut and New York, when, according to polls, they did not feel strong doubts about Kennedy's personal character, honesty, or morality.

In other states, notably Illinois and Wisconsin, where they felt these greater concerns, Kennedy lost the Catholic vote and lost the elections as well.

In Lapko's Bar and Grill, all those interviewed said they are not concerned about questions on Kennedy's personal character. Dennis Michaels, who wore the jacket that supported the "Beast of the East," the Pittsburgh Panthers, said, "Chappaquiddick doesn't bother me and I don't think it bothers the people I know. But I guess it has bothered some people in other places, because if Kennedy hadn't gotten caught with Mary Jo Kopechne, he'd be walking away with the election today -- hell, he'd probably already be president."