A half-mile from the White Houuse Situation Room, is a suite of offices in the capital's low-rent district, one of President Carter's senior advisers was worrying over what to do about the Iranian crisis.

"There's a tremendous impatience across the country now because of Iran . . . and it is a big concern of ours," Tim Kraft is saying in the headquarters of the Carter-Mondale campaign. He is the Carter campaign's political director and he is trying to direct a victory in the important Pennsylvania primary April 22. And right now, things are not going well.

The president's pollster, Patrick Caddell, has just done a survey in Pennsylvania showing that Sen. Edward Kennedy is now leading Carter in the state by 43 percent to Carter's 40 percent.

Just two weeks ago, Carter held a commanding 12-point lead, according to a public survey done by the Gallup Poll for state news organizations. But that was just before the latest hope of freeing the hostages in Iran had collapsed. And now, the Carter political director was clearly concerned.

"The political effect (of the Iran crisis) is dicey and unpredictable," Kraft says. "We know it can't help us -- but the question is, how much can it hurt? . . . With today's frustration, patience is not really a big vote-getter anymore."

Frustration: America's threshold of frustration may have been reached on Wisconsin-Kansas primary day -- it also happened on the April Fool's Day -- when the president personally ran the nation's Iranian crisis hopes up the down staircase, one more time. In an extraordinary 7 a.m. press conference in the Oval office, timed for the morning television news shows on election day, Carter declared that there were "positive signs" out of Iran.

In fact, there have been positive signs; but the lesson of Iran is that nothing is sure until it has happened, and perhaps not even then. Carter's personal effusing proved painfully premature, as Ayatollah Ruhollah Khomeini once again dashed any hopes that the hostages would be taken out of the control of their student radical captors.

America's inflated expectations quickly fell. And the polls, which had already begun to turn against Carter on his handling of Iran, show signs of a plummet.

Louis Harris, first into the field, seemed to capture a new wave of public frustration, in a survey that is worth nothing despite the obvious front-loading of his questions. Just after Carter broke relations with Iran and invoked sanctions on the country, the pollster tested public sentiment with the statement that "What President Carter is doing is too little and too late and not enough" -- and 68 percent of those interviewed agreed.

Seventy-one percent agreed with the statement that "Up to now the United States has been at the mercy of the ayatollah, who had made us look weak and helpless."

And a whopping 77 percent agreed with the statement that "It was a big mistake not to give Iran an ultimatum in the first 72 hours after the hostages were seized."

Back in January and early February, the president's policy of patience and negotiation to free the hostages had the solid support of the American people, according to the polls. But by March, this support had begun to slip. And the latest developments in Iran will surely make the president's political problems worse. Carter's campaign strategists concede.

Iran has always meant more to Carter's political fortunes than just the handling of one crisis. It was always more than just a quick fix that produces a short-lived high. It came to stand for a posture of leadership in trying times, a mix of patience and strength.And -- enhanced by the hardline nature of the U.S. response to the Soviet invasion of Afghanistan -- it supplanted public concerns over the disastrous turn of the Carter economy.

But now the new wave of frustration threatens all of that. Just before the Wisconsin primary, Carter pollster Caddell noted "a significant upward movement" in the percentage of people agreeing with the statement that "Carter cannot handle the presidency" -- and Caddell believed this was directly related to the increased public frustration with the president's efforts to end the Iranian crisis.

Now the state Democratic chairmen are starting to sound alarms. While all 51 chairmen were saying last December that Carter was being helped by the crisis in Iran, half of them are now saying the crisis is hurting the president politically, according to an ABC News survey.

The chairmen are not yet doubting that Carter will again be their party's presidential nominee. But they are having increasing doubts about Carter's ability to defeat GOP front-runner Ronald Reagan in November. This past week, 25 chairmen believed Carter would carry their states and 18 thought Reagan would; just a couple of weeks earlier, 32 named Carter and 12 picked Reagan.

I think in a general election period, if I'm the nominee, that I would certainly participate in campaign activities -- what I've said is that I would not participate as a candidate in the primary season." -- President Carter, March 27

The president spoke of his self-imposed embargo on campaigning while the hostages are held in a wide-ranging interview with Meg Greenfield, editorial page editor of The Washington Post.

To hear the president tell it, this was a longstanding public policy. But actually, according to those at the White House who are in charge of checking such things, Carter never had said publicly that his ban on campaigning was for the primary season only.

He had not said such a thing, back when he first laid down his noncampaign edict, because it would have been unthinkable -- and certainly unspeakable -- to suggest that those Americans who were taken hostage back in the autumn of '79 would still be held prisoner in the summer of '80.

But what was unthinkable and unspeakable last December may soon become factual. This hard international reality has already become a hard fact of political life for the president.

It was with him last week as he read the polls that went in to the Oval Office. And it was with him when he returned to the executive mansion at dusk.

Carter's view from his balcony this week was a postcard of all that is Washington. To the south there was a backdrop of springtime, cherry trees in bloom around the Tidal Basin. And in the foreground, in the bare, grassy Ellipse, was the president's Christmas tree.

It stands alone, stripped of all lights and decorations, save a few yellow ribbons. Once Carter had refused to light the tree, saying he would do so only when the hostages returned -- he had hoped it would be in time for New Year's.