If the House at great moments of crisis tends to resemble a student debating hall, the Senate is very much the upper common room: clubby, cloaked in traditions thatr can make the House of Commons seem ultra-modern, and above all imbued with a sense of its own self- importance.
"The greatest deliberative body on earth," it was once fond of calling itself, until an all-too-visible lack of deliberative skills turned the phrase into a parody. But the illusion persists. All 100 senators look into the mirror each morning and see a future president, it is said. Although nobody from its ranks has been elected to the Presidency since John F Kennedy in 1960, the Senate usually provides the bulk of putative candidates for the nomination.
It is a place of arcane and seemingly immutable rules, yet of procedures that can be subtly modified to suit the hour. Unlike the electronic voting system in the 435-member House, Senate votes are still conducted by roll call: "Mr Kennedy ... Aye, Mr Kerry ... Aye" (or "No" as the case may be). Such is the plodding pace of democracy in the upper chamber.
The clerk will go through the list several times. One by one figures laden with appropriate gravitas move to the bar to record their vote. After- wards they stand by in small huddles, as at a discreet cocktail party. The soft hum of conversation is inaudible by the time it reaches the galleries above.
Fireworks, not surprisingly, are rare. To be sure, great occasions always possess their drama, and so it will be in the impeachment trial. But the very arrangement of the furniture seems designed to extract the passion from of the place. The senator has no bench but a desk-cum-lecturn.
C-Span, the television channel that carries Senate proceedings in their entirety, must also keep its camera fixed on the speaker. Panning shots are barred - for the simple reason viewers would otherwise see that this temple of democracy, apart from him, is usually empty.
But if America's political temperature needs lowering, the Senate is the perfect forum. Its members face election only every six years, compared with every other year for Representatives. Even the fieriest recruit from the House, after a few attempts to liven things up, soon hears the tut- tutting of his peers and acquires the proper decorum.
The Senate, moreover, could never pass anything as contentious as an article of impeachment as narrowly as the 221 to 212 vote that "indicted" Mr Clinton for obstruction of justice.
It needs a 60 per cent majority, or 60 votes, even to end a filibuster and secure a guillotine. And no less than two-thirds, or 67 votes, are needed for an impeachment conviction, or to overturn a presidential veto.
On the face of things, therefore, Mr Clinton looks safe; even if all 55 Republicans voted unanimously, 12 Democrats would have to defect if he is to be driven from office. At any point they could stop the trial.
Senators, however, are less inclined to follow the party whip, and this is a process through uncharted waters. The last time a President underwent an impeachment trial was in 1868. But that America, when Andrew Johnson escaped eviction from office by just one vote, was an utterly different place.
It included just 37 states, compared with 50 today. Communications were in their infancy, the West was largely virgin land. Eight years later, General George Armstrong Custer was defeated at the Little Big Horn.
Impeachment was a novelty then. Even for the 100 wise men of Capitol Hill, it still is today.