ON Capitol Hill, the news of Sen. Bill Cohen's retirement caused a two-step reaction: a look of slack-jawed astonishment followed by a dash for scratch paper.
The Maine Republican's departure calls for a new sketch of the future Senate. Like most of the 13 members planning to retire next year, Mr. Cohen is a moderate long accustomed to brokering deals. He is chairman of the Special Committee on Aging and a deputy majority whip.
Cohen's abrupt exit promises to further scramble the roster of committee assignments, complicate leadership contests, and open the door for another ideological young turk.
Although voters will have a historic opportunity to shape the Senate of the future in November, their votes will have less bearing on the Senate of next year. With so many veteran centrists gone, 1996 could be the year the balance of power in the Senate finally tilts to the edges.
"In some sense, what happened to the Republicans in the House is starting to happen in the Senate," says Barbara Sinclair, a political scientist at the University of California at Riverside. "If we see the same kinds of changes in mood and style we've seen there, we're likely to see more gridlock."
By design, the Senate's ability to function is not served by stubbornness. Any senator who disagrees with a bill can launch a filibuster, which requires 60 votes to overrule, and any change to the rules requires a two-thirds vote.
While the upcoming elections will determine which party controls the chamber and whether they have a filibuster-proof majority, the mass retirement will jumble committee assignments.
On the GOP side, chairmanship of the powerful Appropriations Committee will likely pass from retiring Sen. Mark Hatfield of Oregon, a moderate, to Alaska Sen. Ted Stevens, who is more conservative. On the Democratic side, retiring Georgia Sen. Sam Nunn's seat as ranking member of the Armed Services Committee will now belong to the more liberal Sen. Carl Levin of Michigan.
Although most committees will be taken over by experienced hands, many of them will be less prone to compromise. To that notion, partisans ask: "So what?"
A Democratic staffer says the exodus of centrists will make the Democratic caucus "more cohesive" and better able to strike quickly. Besides, the staffer says, the decline of conservative Democrats makes it more clear what the party stands for. Voters have grown weary of the "mushy middle," he says.
It's an attitude shared by conservative Republicans, who have complained that members like Cohen are a "drag" on their agenda, and that moderates have a tight hold on chairmanships that belies their numbers.
Conservatives also complain that the Senate has acted as a brake on the House's agenda, stalling items from the Contract With America.
When Senator Hatfield cast the deciding vote against the balanced-budget amendment last year, several young conservatives launched a movement to strip him of his chairmanship.
While the attempt failed, a coalition of conservatives persuaded the Republican conference to change the procedure for electing chairmen. Starting next year, chairmanships will be subject to a vote by committee members, rather than seniority.
Senate staffers say this change could depose longtime chairmen who are out of sync with the party or prevent them from taking over. This rule change, combined with the exodus of moderates and the recent fondness voters have shown for ideologues, already seem to spell doom for the "sensible center." But there's more.
If Senate majority leader Bob Dole wins the GOP presidential nomination, he may decide to step down, prompting a race between his three likely replacements: Sens. Thad Cochran and Trent Lott of Mississippi, and Don Nickles of Oklahoma - all of whom are more conservative.
In addition to controlling the floor schedule, the majority leader selects the members of several committees. With such a large freshman class next year, the aide says, a shrewd majority leader could stack these committees to his liking.