In Trent Lott's Senate, they vote for the unthinkable one week, and for the unspeakable the next.

Republicans killed the Test Ban Treaty on Oct. 13 and made the whole world shudder. Tuesday's rejection of campaign finance reform was at least only a domestic embarrassment. But the two disasters had something in common. The debates were marked by a nastiness that used to be considered bad form on the Senate floor. In voting to renew the Cold War, Jesse Helms (R-N.C.) attacked Bill Clinton with low blows that shamed the Senate.

In voting to keep campaigns in the money swamp, Mitch McConnell (R) of Kentucky, Big Money's Big Brother in the Senate, worked over John McCain (R-Ariz.) like a professional hit man. In Lott's Senate, it is no longer enough to defeat your enemy; you must exterminate him. Maybe we should build a barbecue pit in the well so that the spiteful and vindictive can roast their victims whenever they are offended by measures that threaten the status quo. Its defenders can be vicious, as McConnell proved when he baited McCain's frequent use of the word "corrupted" in referring to campaign finance practices.

McConnell hounded him mercilessly. He did not really expect McCain to answer the question of who specifically was "corrupted" by campaign corruption. McConnell knew McCain could not name names--he has enough enemies in the Senate as it is. According to a Senate source, the strategy was to goad McCain into losing his famous temper. McConnell and company hoped to "Rule 14" the upstart, which means that had he said anything personal to another senator, he would be forced to take his seat. It was a humiliation that would greatly diminish the war hero who shows them up so vividly, and who gets what they regard as an outrageously good press. He also needs putting down for his challenge to their safe favorite, George W.

Life in the Hanoi Hilton was good preparation for life in the Lott Senate. McCain has learned to smile at his tormentors. Under severe provocation, he did not blow up.

The debate on the Test Ban Treaty never reached the level of seriousness the subject deserved. Only four Republicans--and McCain was not one of them--dared to come out against a resumption of the Cold War and the arms race. A small effort was made to save some shreds of dignity for the president, but a proposal to shelve the treaty was thought to show softness, and Trent Lott (R-Miss.) made a vote against it a matter of personal loyalty. The president had to be stomped on on the Senate floor.

Similarly, on campaign reform, the majority leader called on his caucus to back him up on keeping McCain-Feingold from coming to a roll call. Had senators been able to vote, they would have passed it. Mitch McConnell stood guard over the rotten status quo, declaiming his passion for the First Amendment. Paradoxically, he is so devoted to free speech, that he denied it to his Lott-tied Senate colleagues.

By its actions, Lott's Senate has declared that the prevention of nuclear proliferation and the de-pollution of politics are not issues of interest to the citizenry. As a general rule, Democrats think of constituents while Republicans think of contributors when drawing up an agenda. But even Trent Lott must occasionally entertain the notion that there are serious and intelligent people outside the Senate chamber who might think these are matters to think--and vote--about.

John McCain, who tried to look buoyant after his final defeat, said he knows this to be the case: "Look at the traction I'm getting in New Hampshire because of campaign finance." McCain is a pauper and a loser by George W. Bush's standard. Bush has $60 million and stands at 40 percent in polls. But McCain, who spends every possible hour in the Granite State, has crept up to 21 points and caused a ripple of concern in the Bush stockade.

McCain also thinks the test ban treaty should be an issue in the campaign. He challenged Al Gore to a debate on the treaty. Gore, who is trying to reignite his damp campaign with the nuclear question, has reinvented himself, but not to the point where he would do anything unconventional. He has declined. He is afraid, apparently, of "elevating" underdog McCain, failing to note he would also elevate himself. Was he afraid that the discussion might drift toward campaign reform, and he might be called upon to defend his own indiscretions and the president's excesses?

"He doesn't need to be defensive," says Sen. Russ Feingold (D-Wis.), the quieter half of the McCain-Feingold bill. "He could turn it all around if he would say he will take no soft money at all, and will adhere to self-imposed spending limits."

Whether Lott likes it or not, the two questions he so cavalierly disposed of are in the campaign to stay.