Between them, Democrat Robert Byrd (search) of West Virginia and Republican Ted Stevens (search) of Alaska have spent 80 years in the Senate, long ago forging a deferential bond that survived the Vietnam War, Watergate, an impeachment and record budget deficits.

But the often warm friendship between two of the most cantankerous and perhaps most feared power brokers in Washington has been frayed over the war in Iraq (search). Their solicitous exaltations of one another replaced by uncharacteristically gruff clashes in recent months.

"I don't know," Stevens, who turned 80 last month, said about his relationship with Byrd. "We'll just have to see what happens now."

Byrd, who turned 86 two days later, said his affection for Stevens is "too deep" to be hurt by one issue. But he added, "I think of this as I think of life, one day at a time, one issue at a time."

Byrd's 45 years in the Senate make him the second longest serving of the 1,875 senators in history, behind only the 47.5 years of the late Sen. Strom Thurmond, R-S.C. Stevens' 35 years rank him 20th.

The two men are linked by more than longevity.

They sit elbow to elbow on the Senate Appropriations Committee, where Stevens is chairman and Byrd the top Democrat and longtime chairman when his party had the majority. That panel is one of Congress' most crucial, responsible for 13 must-pass spending bills every year that control the purses of every federal agency and one-third of the $2.2 trillion federal budget.

It's also one of Congress' most rewarding committees for lawmakers, who use it to win roads, dams and other projects for the folks back home. Almost in a class by themselves, Byrd and Stevens have used their perches over the years to steer vast federal sums to their economically fragile states.

It's a committee that demands bipartisanship to function. Byrd and Stevens know that better than anyone - as they demonstrated just before Congress recessed for Thanksgiving, when they helped craft a massive $373 billion package combining