Like any other politician, the Rev. Jerry Falwell, high priest of electronic evangelists, must bend the knee before the power of the purse and the poll.

The president of Moral Majority held a news conference here the other day to announce a change in the name of his organization. It was no retreat, he said, with his rubbery good cheer and muscular smarminess.

But holier-than-thou, it seems, just isn't selling any more. Fundamental certitudes have wavered in the face of inveterate, although often submerged, American pluralism.

The indications are that if Falwell wishes to realize his goal of making this a "Christian nation," it will not be enough to change the name of the Moral Majority to Liberty Federation; he must change his own.

"He can run but he can't hide," gloated one Democrat whose candidates had been savaged by the Christian Right and the kind of clergy who are trained in Falwell's Liberty Seminary to be "Marines for Christ."

Said John Buchanan, chairman of People for the American Way, an organization founded specifically to counter the Moral Majority onslaught on tolerance, "This is telling us that he is not God's voice in American politics, not the chairman of the Lord's PAC."

Says Roger Craver, who does direct mailings for Democrats, "It shows that extremism never does well for very long in this country."

Ordinary citizens may have trouble telling the difference between the new and the old Falwell, especially since he is president of both the Moral Majority and the Liberty Federation. The melding, he says, was for "a "broadening out on international issues." But as a Majoritarian, Falwell never hesitated to involve himself in world affairs. It is hard to see how as a Federationist, he can exceed his warm embrace of the apartheid government of South Africa or of the tyrant Ferdinand Marcos.

The real reason, he said, is that in the federation, some people will be "more comfortable" than they might have been in Moral Majority.

Translation: Hawky young people, who buy his intrusive foreign policy approach -- one new patriot calls it the "gung-ho, kick-butt style" -- resent his meddling in their private lives on such matters as abortion.

Most citizens, pollsters for both parties now say, all along have been rejecting the pastor of Thomas Road Baptist Church. He is not their idea of what a clergyman should be. In 1984, pollster Louis Harris showed that Falwell had twice as many opponents as fans. Edward J. Rollins, who was political director of the Reagan campaign says, Falwell had "the highest negatives of anyone except Khomeini."

The reverend ruefully noted that the collection plate was light this summer, as he put, it showing "a softness in the donors." The "softness," which has since been corrected, occurred about the time when the foe of secular humanism called Bishop Desmond Tutu of South Africa "a phony." In the opinion of many, this was a connoisseur's verdict. In any case, it did not go down well, even among people who might be expected to be glad to see a little black bishop put in his place.

"It brought back memories of segregation as God's law," says Buchanan.

It was the smashing Democratic victory in Virginia last November that brought home to Democrats the "softness" of Falwell's political clout. The repudiation of Falwell even in Lynchburg, the seat of his $100-million empire, showed that he is a prophet without honor in his own country. One Democratic congressman, who extracted a promise of anonymity after he made the statement, said, "Falwell is going to be as much of a burden to the Republicans as [organized] labor has been to us."

Not everyone, however, thinks of a Falwell endorsement as a millstone. Vice President Bush still covets it. In his name-change news conference, the reverend burbled his enthusiasm for his candidate several times and said archly, if he were to push Bush on the "Old Time Gospel Hour", his Sunday religious program, "it would not only be illegal, it would be very unwise."

Bush, he said with satisfaction, will be the speaker at the Liberty Foundation inaugural convention -- which hopes to raise $12 million for such holy causes as aid to the Contras and "Star Wars" space defense system -- later this month.

Pollster Peter Hart, who found in the early 1980s that Falwell was the least admired public figure he had ever measured, was asked, if in view of the reverend's retreat, politicians might fear him less.

"Probably not," was the answer.

Self-righteousness may be wounded in American politics. It is not dead yet.