CONGRESS : At 92, Thurmond Can Still Fend Off Ouster Attempt : Some colleagues question his mental faculties. But he retains his firm grip on the Senate Armed Services Committee.

At 92, Sen. Strom Thurmond of South Carolina boasts a combination of vigor and virility that is the stuff of legend on Capitol Hill: an exercise fanatic who, at 66, married a 22-year-old beauty queen with whom he has since had four children.

But for the first time in the lawmaker’s 40-year Senate career, colleagues are raising questions about his mental faculties. The resulting low-key drama has generated the kind of intrigue that, while setting the tongues of Senate staffers wagging, has barely broken the serene surface of the upper chamber’s finely honed air of gentility.

Last week, the courtly Thurmond became the target of what he lightly dismissed as a “little power struggle” intended to oust him from the chairmanship of the Senate Armed Services Committee, a position he stepped into when the Republicans gained majority status in the Senate in November.

When it was over, Thurmond’s still-muscled arm maintained a firm grip on the committee gavel.

The gray matter beneath his shock of orange hair seemed intact as well. After attending a state dinner Thursday at the White House with his 19-year-old daughter, Thurmond rose Friday morning after five hours of sleep, drove his daughter to the airport, performed his daily exercise routine of weight-lifting, aerobics and calisthenics, gaveled the Senate to order on schedule at 9:40 and reflected on the minor tempest in an interview with The Times.

“Some people are ambitious and will try to get ahead no matter who it affects,” Thurmond said. Perhaps, he mused, it is a measure of how the Senate has changed in the four decades he has been here “that somebody is ambitious and not willing to wait” his or her turn in the Senate’s pecking order.

The challenge to that pecking order, according to a number of senators and staff members, came from John W. Warner, the Virginia Republican whom Thurmond had elbowed aside to claim the leadership of the defense panel.

Sen. Trent Lott (R-Miss.), a fellow committee member, said Warner recently approached him to suggest a meeting. Lott said he thought Warner wanted to discuss concerns about Thurmond’s hearing agenda, which “had subcommittee chairmen feeling a little penned up.”

Thurmond, who is described by his staff as “very hands-on,” has insisted on presiding over a number of full committee hearings before allowing subcommittees to begin their own deliberations. Many of the panel’s subcommittee members, eager to put their own marks on Pentagon policy, resented Thurmond’s tight grip on the hearing agenda.

“But there was more to it than I thought,” Lott said. He told The Times: Warner, wielding recent examples of Thurmond’s apparent confusion at committee hearings, appeared to be suggesting Thurmond should step aside and let him take over the chairmanship.

The meeting never took place, but word of Warner’s move leaked out, and for days Capitol Hill buzzed with speculation about the incident.

Warner’s angling came in the midst of a difficult period for the Virginia Republican, who had just seen the chairmanship of the Senate Rules Committee also slip from his grasp.

He now faces a difficult reelection bid in 1996 with no committee fiefdom to boast. That campaign could be made all the more difficult by the hostility Warner provoked among GOP leaders for refusing to endorse Republican Senate candidate Oliver L. North in a very tight race last year for Virginia’s other Senate seat, which was won by incumbent Democrat Charles S. Robb.

While Thurmond acknowledged that the challenge may illustrate how the Senate has changed, Lott drew another conclusion: Power grabs have been tried throughout the long history of the Senate, he noted, “and they rarely succeed, so the institution hasn’t changed a whole lot.”

Whether the Senate has changed or not, it is clear that Thurmond himself has made few major modifications in his political routine since switching parties in 1964.

A student of antitrust matters and chairman of the Judiciary antitrust subcommittee, Thurmond this week is to preside over the hot issue of repealing Major League Baseball’s antitrust exemption. In the coming months, he is expected to play a key role in the Senate’s deliberations on anti-crime legislation. An ardent proponent of the death penalty who has likened convicted murderers to animals, Thurmond is certain to press for Senate passage of a measure approved by the House last week that would restrict death penalty appeals.

On the Armed Services panel, he has staunchly defended military budgets and fiercely opposed President Clinton’s plan to ease restrictions on gays in the military.

Several of Thurmond’s fellow senators say that, despite a hearing problem that sometimes makes him appear vague, he remains a shrewd deal maker who keeps a close tally on colleagues’ needs and obligations, and continues to use both effectively.

“With his standing on both sides of the aisle, it would be ill-advised to have any such discussions” about asking Thurmond to step aside, said Sen. J. James Exon (D-Neb.), who has served 16 years with Thurmond. “He is fully in charge.”