'What's in that bill?' The risk of deadline votes.

The first session of the 109th Congress is over, but lawmakers and interest groups are still sorting out what surprises may have been buried in its final bills.

A clause added here or lifted there can shift the fortunes of whole industries and regions. Even insiders say it's tough to follow what's in, what's out, and why.

But even before the results are tallied, observers say it's been a bumper year for add-ons, especially in conference committees behind closed doors.

The year ended in a crush of tough negotiations, late-night votes, and hastily printed bills so vast that few lawmakers had time to read them. Early in the morning on Dec. 19, lawmakers got their first glimpse of the 774-page final version of a nearly $40 billion spending cut bill. The time? 1:12 a.m. House members had to vote on the measure just four and a half hours later.

"It's just one example of the increasing breakdown of any rules in the Congress," says Fred Wertheimer, president of Democracy 21, a public interest group.

"More and more decisions are being made in closed-door conference meetings, where Democrats often aren't allowed. And there is no way to know what is going on often until after it has been passed," he adds.

While the rules say that a conference agreement can't include elements that haven't been voted in either the House or Senate - and can't exclude elements that have been voted in both - they are often violated. It's only an issue if lawmakers - or outside groups in the know - can make it one.

Senate negotiators were stunned to learn that GOP House leaders had added a whole campaign-finance bill to the final conference report on the Defense authorization bill they had already signed. Sen. Hillary Clinton (D) of New York first heard of the changes while on an out-of-town trip.

"It was totally wrong," she says. "It's not a very rational system, when someone can take out what the elected senators and congressmen have voted for and put in extraneous matter that no one has voted for."

At the urging of House GOP leaders, the new language, including curbs on the electoral clout of so-called 527 groups, was added to the bill after the conference had closed.

Senator Clinton called Sen. Carl Levin of Michigan, the ranking Democrat on the Armed Services Committee, who, along with chairman John Warner (R) of Virginia, threatened to withdraw their signatures unless GOP House leaders pulled the measure off the bill. They did.

But another provision, granting immunity from liability to manufacturers of flu vaccine, was added at the last minute to the FY 2006 Defense Appropriations bill. Senate majority leader Bill Frist, who sponsored the measure, says that "appropriate, targeted liability protections" are needed to reestablish a manufacturing base in the US for vaccines. "A pandemic will occur," he says.

After protests from citizens' groups, a previous attempt by Senator Frist to add such a provision was repealed. But last week, Frist, with the approval of House GOP leaders, added the provision back to the Defense bill.

Sen. Edward Kennedy (D) of Massachusetts dubbed the move "a massive Christmas bonus to the drug companies at the expense of nurses, firefighters, and ordinary Americans who will have to take untested vaccines and drugs and get no money for compensation if they are injured."

The practice of adding new provisions in conference, even after the conference is officially closed, "has been used with increasing frequency recently," says consumer activist Jamie Court, president of the Foundation for Taxpayer and Consumer Rights in Santa Monica, Calif. "It's a testament to the power of K Street [lobbyists]," he adds.

At the same time, provisions that have been approved by both the House and Senate can also be stripped from conference agreements, behind closed doors. Although 82 senators and 228 House members passed a nonbinding resolution requiring the Bush administration to report to Congress on secret CIA prisons abroad, the measure was dropped from the Defense Authorization bill in conference - a decision not made public until Rep. Dennis Kucinich (D) of Ohio asked about it on the House floor as the bill was coming to a vote.

"It's brute power," says Sen. Ron Wyden (D) of Oregon. "Much of this is about who's the last in the room, and it reflects badly on the Congress."