The venerable, 84-year-old Stevens is the last of a generation of tough, crusty old Republican titans in the U.S. Senate that once included the likes of Jesse Helms of North Carolina, Strom Thurmond of South Carolina and Phil Gramm of Texas who embodied the GOP's apparently eternal power in the Senate. But he has been toppled at last.

On Tuesday, Stevens was indicted on charges that he accepted more than $250,000 worth of favors from the VECO oil company over an eight-year period from May 1999 to August 2007.

The indictment accused Stevens of hiding "his continuing receipt of hundreds of thousands of dollars worth of things of value from a private corporation."

Stevens is, of course, innocent until proven guilty, but it is astonishing how many people, especially in his own party, are already acting as if his conviction is a foregone conclusion.

Alaska's current Republican governor, Sarah Palin, who made her name by crusading energetically against corruption, has not raised a finger in his defense. Senate Minority Leader Mitch McConnell of Kentucky, a party stalwart if ever there was one, stripped Stevens of all the powerful chairmanships he has held for so long and wielded so energetically on Alaska's behalf. In other words, Stevens has been left to twist in the wind.

Stevens, true to his juggernaut nature, has vowed to fight the indictments. But it looks like Mission Impossible, if ever there was one.

For the crisis could not have hit him, and the Republican Party, at a worse time: Stevens was the foremost champion of opening the Arctic National Wildlife Refuge to drill for oil, and he also strongly supported Republican presidential standard-bearer Sen. John McCain of Arizona in his drive to lift the ban on drilling for oil in all U.S. offshore waters.

McCain had been scoring unexpectedly well on the oil-drilling issue against putative Democratic presidential nominee Sen. Barack Obama of Illinois. But the Stevens scandal will now taint those policies by associating them with accusations of corruption.

Stevens' problems also will weaken the rearguard battle that core Senate Republicans have been fighting to maintain funding across the board for ballistic missile defense programs. Stevens was in the forefront of that, too. The main deployment of the Ground-based Mid-course Interceptors that are the United States' only current realistic defense against intercontinental ballistic missiles is in Fort Greeley, Alaska, and Stevens was one of the program's most powerful champions in Congress.

Democrats have been exposed and have fallen in blatant corruption scandals just as Democrats have, but Stevens' seniority and the timing -- for Republicans, catastrophic -- will switch the national focus back on his troubles at the very moment the GOP can afford it least.

After six successive re-elections to the Senate, Stevens was finally facing a serious challenge this year. He was already at risk of losing his seat to this year's Democratic challenger, Mark Begich, the popular and highly effective mayor of Anchorage, Alaska's largest city. Stevens also looked likely to be at risk from the national trend reported repeatedly by pollsters against the GOP in both houses of Congress. Now, Begich's victory in November looks like a foregone conclusion.

Stevens always carried his share of contradictions. He made his mark on Alaska with endless construction programs and channeling huge sums of federal largesse to his remote and enormous state and was easily the most famous figure in the state's public life for an entire proverbial 40-year biblical generation.

Yet outside the Senate, Stevens remained virtually unknown and exempt from close scrutiny in the U.S. national media.

He loved to preach the GOP values of individualism and enterprise, yet he brought more pork barrel and federal funding to his home state than probably any other senator of his generation.

He did more to integrate remote Alaska with the rest of the United States than any other American during his long period of public service, yet in his fall, he discredited not only himself but also the political system he served and the Senate he loved. He served longer in the Senate than any other Republican in the party's entire history, yet he looks likely to leave it in disgrace. He won every political battle he ever cared about, yet he will be remembered most for the last and shameful one that he looks like losing.

To paraphrase King David's lament for his friend Jonathan in the Bible: "How are the mighty fallen and the weapons of politics perished."