PARIS — An optimist — and there aren't many left in cycling — would say that the only advantage for the scandal-mired sport is that things can't get much worse.

The Tour de France is in agony, and it has gotten there by failing to learn from the past — from as long ago as 1998 and as recently as last year.

After Lance Armstrong won cycling's premier event for seven straight years from 1999 to 2005, the Tour has been going downhill faster than the riders on their descent from the Alps.

But even the Armstrong years, and the decades that preceded them, were riddled with doubt. There were questions about how a cancer survivor managed to rebound enough on a race as tough as the Tour. While Armstrong always insisted he was clean and was never sanctioned, riders he beat — including 1997 champion Jan Ullrich and Italian Ivan Basso — are now out of the sport in disgrace.

Italian rider Cristian Moreni didn't learn from the case of American Floyd Landis, the 2006 Tour winner who isn't defending his title because of doping charges still hanging over him.

Like Landis at the last Tour, Moreni tested positive this year for the male hormone testosterone. Unlike Landis, who maintains his innocence and spent heavily on lawyers, Moreni admitted wrongdoing and waived his right to a follow-up test, according to his team, which pulled out of the race Wednesday.

Despite their tough anti-doping talk, Tour organizers gave a wild card invitation to Alexandre Vinokourov of Kazakhstan and his Astana team. That proved to be a huge mistake, because Vinokourov and his team were pulled from the race on Tuesday after he tested positive for a banned blood transfusion.

But those cases were merely a sideshow to this year's real bombshell: the case of race leader Michael Rasmussen of Denmark, who was sent home for lying about his whereabouts during drug testing.

He had said he was in Mexico and couldn't send e-mail to let everyone know where he was because he didn't have a computer. But a former rider, Davide Cassani, said he had seen Rasmussen in Italy in mid-June. Rasmussen also said he had sent at least one letter to inform people of his whereabouts, although it didn't seem to arrive.

"Michael told the team that he was in Mexico and it turned out ... that he wasn't in Mexico but was in Italy," said Jacob Bergsma, a team spokesman. He said its sponsor, Rabobank, ordered Rasmussen out of the race.

Patrice Clerc, president of ASO, the company that runs the Tour, was even more direct. "There was, in his behavior, an evident intent to cheat," Clerc said.

Bergsma said Rasmussen had subsequently admitted that he was, indeed, in Italy. But that wasn't what Rasmussen told the Danish tabloid BT.

"This is too crazy. I do not get it. This is totally cuckoo," he was quoted Thursday as saying. "I was not in Italy. Not at all. This is the story about a man who claims he recognized me."

Unfortunately for the Tour and for those still-clean riders who trailed in his wake, Rasmussen had been wearing the race leader's hallowed yellow jersey for eight days by the time he was told to pack his bags.

Tour director Christian Prudhomme, clearly eager to get the Rasmussen scandal behind him, described his withdrawal from the race as "the best news of the week."

But the affair left the race's credibility in tatters, and cycling may be running out of time.

France Soir newspaper ran a mock death notice for the Tour, saying it died Thursday "at age 104, after a long illness."

The newspaper Liberation said in an editorial that "the Tour must be stopped."

"This procession of cyclists has been transformed into a caravan of ridicule," Liberation wrote. "If the organizers really want to save cycling, they should stop the competition and declare a pause of a few years, enough time to treat these athletes-turned-druggies."

The fight against doping resembles the Tour itself, a long and arduous struggle with many ups and downs.

Although some European sponsors are distancing themselves from the Tour because of the scandals, U.S. companies are more hesitant to pull their logos from the jerseys, helmets or team vans.

It shouldn't be forgotten that the Tour used to be a great race that has inspired generations.

Fans were still turning out for Thursday's 17th stage from Pau to Castelsarrasin.

"It's a beautiful race and it would be too bad if it disappears," said dental technician Ariel Couderc, 62, from Pau. "This was a case of no pain, no gain, and I hope the expulsion will help purify the sport. But yeah, we have our doubts about the person who is first, and whether he is really the best or not."

The daily sports newspaper L'Equipe took a more positive spin, saying the problems represented an opportunity for organizers to clean up the Tour. But it warned them to "seize it quickly."