Philippine President Ferdinand Marcos, calm and articulate in his crisp white shirt, appeared almost nonstop on U.S. television over the past two weeks, but his image in the United States appears to have deteriorated sharply, especially among his former friends.

While some of his supporters thought Marcos did well in the nine televised interviews he gave between Feb. 5 and Feb. 10, many conservatives said they were appalled. Some of them, complaining that news coverage was wildly biased against Marcos, nevertheless are backing steadily away from him.

"He kept thinking he could salvage himself on national television, but he didn't do too well at it," said one key Senate Republican staff member.

"Conservatives are obviously in a pickle on this," said Sen. David F. Durenberger (R-Minn.), chairman of the Senate Select Committee on Intelligence. He called for Marcos to step down.

"I'm not condemning the election. It took a lot of nerve on his part, knowing he would have to shoot a few more people and stuff a few more ballot boxes in front of the world," Durenberger continued. "But it was irrelevant other . . . than to show how important it is for one person to step aside for the good of 50 million Filipinos."

Jeane J. Kirkpatrick, the doyenne of conservative thought, wrote sympathetically about the Philippine presidential election in her regular Sunday newspaper column last week, but altered her view on Saturday to lament that "deaths, violence, chaos and charges of fraud on election day" meant that a praiseworthy "rowdy, American-style campaign degenerated into a dismal and chaotic scene. Manila was far from the 'Citadel of Democracy' proclaimed by Gen. Douglas MacArthur."

John Deardourff, a media consultant whose clients are overwhelmingly Republican, said Marcos' TV interviews, even if they had been perfect, could not have competed with news coverage of violence and incidents of apparent fraud.

"One report of goon squad tactics by alleged Marcos supporters is certainly going to offset anything Marcos can say about himself," Deardourff said. "Enthusiasm for Marcos has probably dropped like a rock in this country, ever since he began to come into focus."

The focus was too close for some. Marcos "really never gave a straight answer" in his interviews, said a conservative senator who asked not to be named. "I thought he really hurt himself." He cited in particular Marcos' dismissal of questions about his World War II record and his later suggestion that he might invalidate the election if there were too many fraud charges.

Columnist Benjamin J. Wattenberg, a conservative Democrat, said in his column yesterday that while the campaign unleashed powerful forces for democracy, it didn't do much for Marcos' image. "Marcos and his thugs may indeed be corrupt -- but they are surely inept," he wrote. "Watching them operate, one wants to present marksmanship medals to the gang that couldn't shoot straight."

Some conservatives said they had been worrying privately about corruption and economic failure in the Philippines and were not surprised by reports of fraud and violence.

"I certainly don't think this election was anything that either side can be particularly proud of, but in the Philippines they rarely are," said William Rusher, publisher of the conservative National Review. "The media handling of the campaign was a national disgrace . . . . I am slowly trending toward Marcos in the teeth of the media's totally lopsided campaign to smear him."

Kirkpatrick said in an interview that she had thought privately that Marcos' challenger Corazon Aquino would win the election because of Filipinos' evident desire for a change.

"I had assumed throughout that the government of the Philippines would finally prove incapable, simply at the technical level, of pulling off large-scale electoral fraud," she said. "There were more problems than I expected there would be."

"This hasn't raised my concern about anything that wasn't already there," said W. Bruce Weinrod, director of foreign policy and defense studies at the conservative Heritage Foundation. "But it is what you might call an action-forcing event, making people comment in a way they don't normally do."

Rep. Robert L. Livingston (R-La.), a conservative and a member of the official U.S. observer delegation to the elections, said there was "no doubt" that Marcos' credibility has suffered. "He called for the election and he called for the observers, and his supporters seemed to be responsible for the majority of the manipulations," Livingston said. "The two don't jibe, and he's got to pay the price."