For many politicians, hubris isn't merely an occupational hazard, it's a central facet of personality. And often, the more successful the official, the more pronounced the trait. The confidence that you have the capacity to lead, the conviction that you, above all others, should be chosen to do so — these can easily edge into the kind of thumb-in-the-eye-of-the-gods arrogance that inevitably invites downfall.

Hubris, indeed, can be seen at the core of the twin dramas that have ensnared two top congressional leaders. But the fault takes many forms, and its manifestations in the cases of Senate Majority Leader Bill Frist, R-Tenn., and former House Majority Leader Tom DeLay, R-Texas, are as different as the two lawmakers themselves.

Frist's hubris is that of the man whose overweening self-regard is such that he can't imagine that anyone would question his behavior; DeLay's is that of the man whose relentless drive for power is such that he doesn't care what people think.

To put it in mythological terms, Frist is Narcissus, so taken with his own image that he came to ruin; DeLay is Icarus, so convinced of his ability to flout the limits that apply to ordinary mortals that he became the instrument of his own destruction.

In the classic arc of hubris, the flawed figure offends the gods and is brought low. It's too soon, of course, to know whether the Frist and DeLay plot lines will follow this trajectory. There is, right now, more smoke than evidence that Frist engaged in any insider trading. And though DeLay has been indicted, his nemesis, Texas prosecutor Ronnie Earle, either lacks explicit proof of DeLay's own contribution to the alleged campaign finance conspiracy or is cannily hiding his best cards.

Yet the experience of their predecessors of both parties — Jim Wright, Tony Coelho, Newt Gingrich, Bob Livingston — is ominous for the two politicians. It suggests a riff on Euripides: Whom the gods would destroy, they first elect to leadership posts.

If so, the seeds of Frist's folly were planted at the outset of his political life. The flawed Fristian premise was that he was more doctor than politician; that he could transplant the wisdom and compassion of the heart surgeon into a new legislative career focused on healthcare.

But at the same time, Frist, the scion of a family that had made its fortune in the field, dismissively rejected the notion that his continuing to own millions of dollars of stock in the family company might call into question his judgment on these very issues. So transfixed was he by his own self-image and his conviction that his character was above question that he could not understand how this irreducible conflict would appear to others.

The ironic twist here is where the Narcissus analogy falls short, because in the end Frist would have been better off if he had hewed to his original self-absorption. The fateful move that has produced a pair of federal investigations is Frist's decision to reverse course — a decade too late and on the eve of a presidential bid.

It's this smug and disingenuous maneuvering, I suspect, that — even without a trail of damning e-mails or whispered conversations with company insiders — may sink the senator, politically rather than legally. For if Frist intended to put the conflict-of-interest issue to rest by dumping the stock, his flip-flop unintentionally produced just the opposite effect. And it evokes other Frist positions that seem driven more by political calculation than fundamental conviction: his diagnosis-by-video of Terri Schiavo and his shifting stances on embryonic stem cell research.

The DeLay drama is different — but with, perhaps, its own ironic conclusion. The former majority leader is no youth, but he was, like Icarus, heedless of warnings that he was dangerously, repeatedly pushing the limits — in DeLay's case of ethics, not physics.

His thuggishness in the pursuit of his political interests seemed to know no bounds: bullying corporations and trade groups not to hire Democrats, and threatening them with legislative consequences if they dared to do so; keeping pointed lists of what lobbyists were giving — not just to Republicans but to the other side — and unsubtly intimating that these totals would matter when it came to access and actions.

"In view of the number of instances to date in which the Committee has found it necessary to comment on conduct in which you have engaged, it is clearly necessary for you to temper your future actions," the House ethics committee warned DeLay last year.

As a practical matter, not a legal one, it may not make much of a difference if DeLay turns out to be right, this time around, in arguing that he is the innocent victim of implacable political foes.

He has flown too close to the sun so often that the wax on his wings has already softened and the feathers are fluttering into the sea.

Ruth Marcus is an editorial writer at The Washington Post.