THE despair in the Senate aide's voice was palpable: Arlen Specter was about to suspend his presidential campaign. Another voice for political moderation was leaving the stage.
Gov. Pete Wilson of California had already quit the race for the GOP nomination. Colin Powell never got in. Nancy Kassebaum, the popular centrist Republican from Kansas, had just announced she's retiring from the Senate.
''I'm afraid this all just stokes the fires of the conservatives,'' says the aide to Senator Specter (R) of Pennsylvania. ''Maybe the Christian Coalition is winning.''
Mr. Wilson and Specter, to be sure, had problems as candidates. Wilson was bland and entered the race late. Specter, who dropped out Wednesday, exudes as much warmth as a New Hampshire January. But the overall effect of all the recent political departures, including the retirements of many other moderates from Congress - such as Sens. Sam Nunn (D) of Georgia and Bennett Johnston (D) of Louisiana - is a feeling that the center is hollowing out.
More and more, politics seems dominated by activists of all kinds. The result could be further loss of public civility and an increase in legislative polarization.
Moderate activism - the very notion is an oxymoron - has yet to find the legions of loyal foot soldiers that have energized politics, particularly conservative politics, today. ''Here's the difference,'' says Ann Stone, a GOP fund-raiser who runs the group Republicans for Choice. ''On weekends, moderates are taking their kids to piano lessons or going on picnics. Conservatives are taking their kids to political conventions and handing out leaflets.''
The frustration for moderate activists is that they believe they represent the majority of Republicans. ''The conservative wing accounts for maybe one-fifth to one-third of the party, depending on the issue,'' says Ken Ruberg, head of the Republican Mainstream Committee, which is organizing at the state level. ''There are issues that motivate the mainstream. From 1989 to '92, it was choice [abortion]. This year, the environment is taking on salience.''
An irony for Republican moderates in Congress is that they now constitute an influential swing group. The Republican majority is narrow enough in both houses that, on some issues, the moderates can win concessions on legislation.
The same holds true for conservative Democrats. They have enough in common with Republicans that they can often bridge differences between the two parties. A balanced-budget plan drafted by conservative Democrats is gaining notice as a possible blueprint for an ultimate budget agreement between the White House and the Republican leadership.
In the recent budget impasse that partially shut down the federal government, Sen. James Exon (D) of Nebraska was key in finding a solution. But, like many of his conservative Democratic colleagues in the Senate, he's retiring at the end of this term.
On the '96 presidential stump, the near-miss presidential campaign of Mr. Powell is the ultimate ''might-have-been'' to moderates like Ms. Stone. As the general weighed his decision, a groundswell of moderate support mounted, both from the public and from the political establishment. It's possible, say analysts, that Powell could have single-handedly filled the void in the middle and rescued the level of public debate from its partisan depths.
But Powell didn't have the ''fire in the belly,'' he said. He couldn't bridge that chasm between moderation and activism. He also apparently couldn't stomach the idea of conservative activists digging into his and his family's lives.
The sight of ''family values'' conservatives gunning for him on the eve of his final decision left Powell unenthusiastic about a campaign.
WHICH leaves Sen. Bob Dole of Kansas as the likely GOP nominee. Long viewed as a moderate, Senator Dole is engaging in the tried-and-true method of tacking to the right to attract the support of his party's conservative activist wing, to be followed, presumably, by a shift back to the middle to appeal to the general electorate.
This worries Republican moderates, a constituency usually defined as fiscally conservative and socially libertarian. On abortion, the flagship issue of Specter's campaign, Dole has almost wholly accepted the conservative position. In his anti-abortion stand, Dole has held back in two ways: He has refused to sign a pledge to keep the anti-abortion plank in the GOP platform, and he has refused to promise to select an anti-abortion running mate.
But pro-abortion-rights moderates are concerned anyway. They worry that the primary process, which is dominated by conservative activists, will nevertheless lock Dole into the conservative social agenda. Now that Congress is decidedly anti-abortion, an anti-abortion president could spell trouble for abortion rights.
''Moderates are saying they need a sign that he [Dole] won't go off the edge of the earth,'' says Stone. If they decide he has, ''pro-choice Republicans will vote against Dole to keep Congress in check.''