Undiscussable: a question in the Senate.

JUST hours after word got out that South Dakota senator Tim Johnson had fallen ill with a serious brain ailment, minority leader Mitch McConnell's office got in touch with Republicans around the Senate. The message: Do not--repeat, do not--talk about the political implications of Johnson's illness. Besides being genuinely concerned about Johnson, Republicans worried about their image and didn't want even to hint that they were seeking any advantage from their Democratic colleague's misfortune.

But the fact is, given the narrowness of the Democrats' 51-49 margin in the new Senate, Johnson's illness got people talking. If Johnson were to die, or had to leave the Senate, and if he were replaced by a Republican appointed by South Dakota's Republican governor, a 50-50 Senate would swing to GOP control, with Vice President Dick Cheney's tie-breaking vote. The stakes were clearly high. Still, when the Senate convened in early January--with Johnson still hospitalized--Republicans said pretty much nothing about the politics of it all.

It was a far cry from early 2001, when Democrats capitalized on what was known as the "Strom Thurmond Death Watch." At the time, the Senate was split 50-50, plus Cheney's vote, meaning that a switch of one senator would throw control into Democratic hands. That, of course, is what happened when Vermont's James Jeffords left the GOP in May 2001, but nobody knew that in January. Instead, Democrats acted on the possibility--the hope?--that South Carolina's Strom Thurmond, then 98 years old, would not survive the 107th Congress. If Thurmond died, his replacement would be chosen by South Carolina's Democratic governor, putting Democrats in power.

So when the Senate first got together in January 2001, Democrats insisted on placing a special provision in the rules. Their agreement with Republicans called for Senate committees to be split 50-50 between the parties, with the GOP holding the chairmanships. But the rules of the Senate, once made at the beginning of a new Congress, usually stay in place for two years. Knowing Thurmond's health--there were also eyes on North Carolina's Jesse Helms, then 79 and not doing well--Democrats came up with the following clause: "Such committee ratios shall remain in effect for the remainder of the 107th Congress, except that if at any time during the 107th Congress either party attains a majority of the whole number of senators, then each committee ratio shall be adjusted to reflect the ratio of the parties in the Senate ... and the committee chairmanships shall be held by the party which has attained a majority of the whole number of senators." Under the arrangement, if a Republican died--there weren't any Democrats on the death watch at the time--the turnover to Democratic control would be quick and clean.

Party supporters in the press got the message. "If Democrats, who control no branch of the federal government, seem oddly complacent these days, it may be because they believe they're holding an ace in the hole," wrote Slate editor Jacob Weisberg in March 2001. "Their secret weapon is the grim reaper." "Is it in bad taste to talk about the death of Strom Thurmond before he has actually died?" asked The Nation's William Greider. "Probably, but hey, everyone in the Washington power corridors seems to be talking about it." (Such talk was spurred on by a New York Times story headlined "A Hushed but Vital Issue: Thurmond's Health.")

Compare that with statements in the conservative opinion press after Johnson fell ill. Everyone should "lay off" speculation about Johnson, National Review Online wrote in an editorial on December 15. "We would rather see a healthy Senator Johnson, and the Senate in Democratic hands, than an ill Senator Johnson and the Senate controlled by the GOP." Republicans and their supporters simply didn't want to entertain the idea of a changed Senate.

Those sentiments apparently extended to the Republican leadership as well. In late December and early January, when the new Senate was organizing itself under Democratic control, Republicans did not insist on a provision like the one Democrats fought for in 2001. They did briefly consider it--in fact, some Republicans discussed the issue before Johnson fell ill, when Sen. Joseph Lieberman won reelection as an "Independent Democrat" and declined to say definitively that he would always stay in the Democratic party. But few believed Lieberman would switch, and nobody wanted to talk about Johnson. So there was no Republican support for putting a 2001-style clause in the rules.

"We didn't do what they did in '01," says a leadership source. "You'd have Republicans in the position of saying, 'Hey, we think Tim Johnson is going to die any day now.'" If they violated the taboo, GOP leaders felt sure they would be pilloried by Democrats and the press. "They'd say, 'There's a senator in the hospital, and all Republicans are thinking about is how to get power back--after the American people spoke,'" says the source.

So there is no clause. What would that mean if Johnson were to die, or Lieberman were to defect? The GOP leadership source argues that Republicans would still take over, even without a specific provision. "You can at any time in a Congress--at any time--say, 'We're submitting this new committee slate that says Arlen Specter is chairman of the Judiciary Committee, and Charles Grassley is chairman of the Finance Committee, and so on," the source says. He concedes that Democrats might try to block such a move. But should that occur, the aide says, the Republican majority would prevail. "We would destroy them--it just wouldn't stand."

In the long term, he's right; if Republicans became the majority, they could ultimately force Democrats to give up control. But, unlike 2001, it probably wouldn't be quick, and it wouldn't be clean. "At some point, the Democrats would have to make an accommodation," says a Republican veteran of the 2001 Senate fight. "It's a question of how quickly they would make an accommodation and what concessions they could get Republicans to make in exchange for it." In other words, Democrats would likely extract a price--power-sharing arrangements, better representation on committees--to hand over power to Republicans without a time-consuming and messy fight.

Of course, no one knows what will happen. In the end, Strom Thurmond made it until the end of his term, and Jesse Helms, although no longer in the Senate, is with us still. Nevertheless, a number of observers believe Democrats were smart to insist on a measure providing for an orderly turnover of Senate power, and Republicans were not so smart in failing to do so. Yes, death and debilitating illness are unpleasant topics. And none of us, whatever his age, knows when his time will come. But we all make plans for that eventuality. All of us, save Senate Republicans.