WASHINGTON — To many who know him, Sen. Sam Nunn (D-Ga.) appears to have undergone a remarkable transformation since he decided last month not to run for President.
Once known as a painfully cautious politician, Nunn, 49, the bespectacled chairman of the Senate Armed Services Committee, is suddenly beginning to wield his considerable influence in Congress with the confidence and aplomb of a true partisan power broker.
And at the White House, where his actions are closely monitored, Nunn is quickly gaining a reputation as President Reagan's chief Democratic nemesis in Congress.
"This is a different Sam Nunn," remarked a Republican Senate aide. "This is not the same guy--the little Mr. Peepers--that we've known over the past few years."
Republicans were stunned recently by what they viewed as Nunn's highhanded tactics in threatening to hold up the Supreme Court nomination of Robert H. Bork until the GOP ended its four-month filibuster of the fiscal 1988 defense spending bill. A few days after his threat, the filibuster was broken.
Moreover, Nunn has been the driving force behind the current Democratic challenge of Reagan's policy on arms control and his decision to provide U.S. Navy escorts for reflagged Kuwaiti oil tankers in the Persian Gulf. And it is widely expected that Nunn will soon force the President to back down on his plans to conduct tests in space of his controversial "Star Wars" missile defense system.
When it comes to power politics, Nunn is certainly no novice. Even in previous years, he was widely regarded as one of the Senate's most influential members. "He's always had that E. F. Hutton quality--when he talks, people listen," said political scientist Norman Ornstein.
But analysts such as Ornstein see the Nunn who is emerging now as a senator of genuine stature, an Armed Services Committee chairman who will be mentioned in the same breath with such giants as the late Sen. Richard B. Russell and Rep. Carl Vinson. Both were Georgia Democrats who served as armed services chairmen in the 1950s and 1960s; Vinson was Nunn's great uncle.
It was the agony of deciding whether to run for the presidency that seems to have bolstered Nunn's enthusiasm for his Senate position. According to his colleagues, Nunn realized during his deliberations that he could have nearly as much influence on national defense by simply using his current position to shape foreign and defense policy.
"When you look at the careers of men like Richard Russell and Carl Vinson, you see that these two men had more to do with the strength of this country than all the Presidents combined," remarked Roland McElroy, a former Nunn aide.
Although Nunn insists that some commentators are exaggerating the recent change in his behavior, he acknowledges that he is being seen in a new light.
"As soon as you are mentioned for President by the 'Great Mentioner,' you are under a cloud," he said in an interview. "People look at you differently. The same is true when you decide not to run. But I think it's mostly in the eye of the beholder."
Nunn, who was under considerable pressure from many influential Democrats who wanted him to run for President, admits he has felt considerable "mental relief" since he decided on Aug. 27 to forgo the opportunity. "When you get something like that out of your mind, your mind is probably freer to work on other things," he said.
A notorious perfectionist, Nunn said he decided against running not because he judged his chances of winning the nomination to be poor but because he believed he could not seek the presidency without damage to his stewardship of the Armed Services Committee.
"Obviously, if I was dying to be President of the United States, I'd be a candidate," he added. "To me, I have other priorities that have to assume first place."
Nunn said his recent willingness to challenge the Administration stems primarily from the disappointment he felt last year after President Reagan's meeting with Soviet leader Mikhail S. Gorbachev in Reykjavik, Iceland. Reagan proposed to eliminate "all ballistic missiles," Nunn said, without fully grasping that many nuclear weapons, such as those carried by bombers and cruise missiles, would remain.
"That had a real effect on me," Nunn said. "When you see the President of the United States proposing something that had never been thought out by staff--something that he didn't even understand--it does remove the presumption of an Administration having a firm grip on what its own philosophy is on arms control."
Whatever the reasons for Nunn's transformation, Democrats in the Senate--particularly liberals--have been surprised and pleased by it. A staunch conservative who has been out of step with the majority of his party for many years, Nunn is clearly becoming more partisan, if not more moderate.