Not until consultants David Keene and Donald Devine decided Sen. Robert Dole should celebrate the evening of Feb. 23 at the scene of his midwestern triumph instead of proceeding to the Super Tuesday South did campaign manager William Brock decide that they must go.

What caused him to kick them off the plane and out of the campaign was fear that the two conservatives were taking over the campaign. ''I think Brock felt very threatened,'' a senior campaign official not allied with either side told us.

Here is one instance of campaign disarray in which Dole, the congenital micromanager, is more victim than perpetrator. Once Brock settled on his purge, the senator had no options. He could scarcely say no to Brock, forcing his resignation as manager and demolishing the campaign structure in the heart of the primary season. Instead, Dole was deprived of his two most experienced national operatives and two best links to the conservative movement.

It was Keene and Devine to whom a distraught Dole turned at his low point following the New Hampshire debacle. Inability to get an antitax commercial on television there in the campaign's closing hours confirmed suspicions about the seaworthiness of the costly structure put together by Brock.

Since resigning as secretary of labor to rehabilitate Dole's ramshackle campaign last fall, ex-Republican national chairman Brock has decreed that all lines of communications to the candidate run through him. Devine, a nationally known right-wing activist for 20 years and a former senior Reagan administration official, was relegated to sideshow campaigns and ordered to report to Brock's subordinates.

But Keene, current American Conservative Union national chairman, whose presidential campaign experience dates back to 1976, was outside Brock's lines as Dole's personal consultant. On Friday, Feb. 19, a disconsolate Dole telephoned Keene and asked him to come aboard the plane the next morning at 7.

Soon thereafter, Devine was called in from Minnesota. With the two right-wingers aboard to talk politics, Dole's spirits revived. On Monday, Feb. 22, another Dole adviser -- ex-New Hampshire attorney general Tom Rath -- told Brock the senator needed a senior aide at his side at all times and that they should rotate airborne duty. Brock did not disagree and even said Keene had performed useful service following the New Hampshire defeat.

That was before Brock learned Keene and Devine had canceled plans for Dole to go south Tuesday night and instead would be in Sioux Falls, S.D., basking in adoration of supporters after a double win in South Dakota and Minnesota. Brock was understandably furious that tactical decisions were being made on the plane instead of at headquarters. His anger intensified with news that the airborne planners scheduled a new stop in Oklahoma, a Super Tuesday state.

Word spread that the campaign manager would arrive in Sioux Falls Tuesday night for a showdown. Brock denied any such plans to us, and his friends suggested he might quit the campaign. In fact, he had decided to board the plane Wednesday night in Charlotte, N.C., and to fire the two conservatives the next morning in Jacksonville, Fla.

That decision was made before Brock was aware of two events cited in some reports as reasons for the purge: first, our report over CNN of Keene and Devine making airborne strategy; second, a secret Keene memo to Dole proposing a campaign overhaul in which Brock would become largely a spokesman and Devine would become operational head of state campaigns.

Dole never saw it. The more cautious Devine convinced Keene he was reaching too far, and Keene asked a secretary to delete the memo from his computer. She did not, and Brock later was given a copy, which fed his anger.

The evidence as to who was right rests against Brock. Dole should have been at the scene of his triumphs Feb. 23. Other Dole supporters have always felt that the senator can, at best, manage a holding operation in the South Super Tuesday.

But besides disputes over tactical judgment, there remains the question of who will control the campaign. Dole's old friends suspect that Brock lacks the single-minded devotion to the candidate of Bush's Lee Atwater. The campaign manager could have performed a signal service for the candidate had he managed to reassert his own authority without depriving Dole of two, though sometimes fractious, helpers.