Harry Reid, the Senate's top Democrat, makes frequent trips to his home state of Nevada. Over the past four years, his bills at Caesars Palace, Mandalay Bay and other Las Vegas establishments have totaled more than $125,000, according to PoliticalMoneyLine, a nonpartisan organization that tracks money in politics.

Mr. Reid charged these expenses to a special campaign account called a leadership political-action committee, or leadership PAC. The primary purpose of such accounts is to funnel money to other congressional candidates in need of campaign cash, especially those in close races.

But in recent years, leadership PACs on both sides of the political aisle have spent an increasing portion of their money for things other than contributions to candidates, the records show. Those expenses ranged from hotels and meals for the lawmakers who set up the PACs to flowers and jewelry for political supporters, the records indicate.

This shift in spending is notable in an election cycle that features so many closely contested races. With only a few days remaining before next week's elections, many candidates have run short of funding for all-important television advertising, and every additional dollar contributed by leadership PACs is important.

On average, the leadership PACs of Republicans and Democrats in the House contribute 40 cents to candidates for every dollar they raise, an analysis of the spending data shows. In the Senate, Republicans contribute about 30 cents for every dollar they raise, and Democrats contribute about 20 cents.

Leadership PACs aren't subject to the same campaign-finance rules as the re-election accounts of individual congressmen. Election law, for example, bars politicians from using their own campaign funds to cover personal expenses. Those rules don't apply to leadership PACs, campaign-finance lawyers say.

Lawyers say there are few limits on what leadership PACs can pay for. "If a lawmaker wanted to pay his or her mortgage out of their PAC, they could do it," says Jan Baran, a campaign-finance lawyer with Wiley Rein & Fielding in Washington.

A spokesman for Mr. Reid says all expenses the senator charged to his leadership PAC were appropriate and were related to campaign or fund-raising business, including meals in Las Vegas with political supporters. Lawmakers with leadership PACs contend that, regulations aside, donors would never tolerate the use of money for personal expenses.

But critics say the rules that apply to PACs, which chiefly govern the size of contributions, aren't rigid enough, and give the lawmakers too much latitude over how money is spent.

"My impression is that a lot of people use leadership PACs as a slush fund," says Rep. Joel Hefley, a Colorado Republican and former chairman of the House Ethics Committee, who is retiring at year's end. Lawmakers use their accounts, he says, to pay for "all kinds of things that can be justified, but certainly are questionable." Mr. Hefley, who says he believes congressmen spend too much time raising money, introduced a bill this year to outlaw leadership PACs. So far, no other lawmakers have endorsed it.

Nearly half of the 535 members of Congress, in both parties, have leadership PACs. Through Aug. 30 of this election cycle, 260 leadership PACs have raised about $100 million and have disbursed about $33 million to colleagues' election campaigns, analysis of the PoliticalMoneyLine data shows.

Both the number of leadership PACs and the money they have contributed to candidates have increased by 20 percent since 2002. But their operational costs -- the money spent on staff salaries, fund raising, flights, meals, everything other than campaign contributions -- have doubled to $53.3 million over that period, analysis of the data shows.

Leadership PACs have been around for a couple of decades, but until recently, only a few congressional leaders operated them. In the mid-1990s, Rep. Tom DeLay of Texas, who left Congress this year, founded a leadership PAC and began encouraging other Republicans to do the same. He urged his colleagues to use the PACs to funnel political contributions into competitive elections their party needed to win to retain their congressional majority.

Lawmakers who want to give money to a vulnerable colleague are barred by law, under most circumstances, from sending more than $4,000 from their own re-election accounts per two-year election cycle. By setting up a leadership PAC, lawmakers can dole out as much as $10,000 per cycle to a candidate. Corporations can donate up to $10,000 per election to the PACs. Those limits are more than twice the legal limits for conventional re-election accounts.

Lawmakers in safe seats often direct money to colleagues who are struggling. In many cases, the grateful recipients support these donors in subsequent congressional votes on leadership posts.

For example, when House Republicans voted to replace Mr. DeLay as majority leader earlier this year, most backed the candidate who had given them the most leadership-PAC money, records indicate. Republican Rep. John Boehner of Ohio, who was voted the new majority leader, had donated more money to his Republican colleagues than did his opponent, Missouri Rep. Roy Blunt, according to a study by the Campaign for a Cleaner Congress, a congressional watchdog group.

This year, with only a few days remaining before the elections, some candidates on each side of the aisle don't have the money they need for the final push, and they aren't getting as much as hoped for from leadership PACs.

Rick Santorum of Pennsylvania, the Senate's third-ranking Republican, spent nearly $1,500 over the past six years at fast-food restaurants, according to PoliticalMoneyLine, which analyzes Federal Election Commission records. Records show his PAC paid $22 at a Burger King in Virginia, $6 at a Boston Chicken in West Chester, Pa., and $15 at a Subway in Pittsburgh. In addition, it paid for $600 of Starbucks coffee.

"I'll be on a trip for a candidate and I'll stop in to buy a cup of coffee or a sandwich," he said in an interview Wednesday. "I don't eat at fancy restaurants, so when I'm traveling I just eat at cheap places. We don't have $500 restaurant bills at Charlie Palmer's. ... That's not how you spend donors' money."

Mr. Santorum has handed out to other candidates 20 cents of every dollar his leadership PAC has raised over the past four years. The account, called Fight PAC, raised $3.5 million and distributed $700,000 to Republican candidates and causes.

Records show that over the past six years, Mr. Santorum's PAC has paid $1,900 for limousines, $3,000 for flowers, $4,100 for art and framing.

Robert Traynham, the senator's spokesman, says the PAC's goal is to elect more Republicans to Congress, and that it is permissible for Mr. Santorum to bill the PAC for "reasonable administrative expenses."

Rep. Tom Reynolds, who is in charge of organizing the Republican party's effort to retain a House majority, has dipped into his leadership account to pay $650 for stationery design and $447 for a dinner meeting for his staff at an Irish bar on Capitol Hill.

Steny Hoyer of Maryland, the House Democratic whip, spent $2,315 on L.L. Bean shaving kits for political supporters, staff and other politicians, and $405 on flower arrangements for several funerals, according to PoliticalMoneyLine. A spokeswoman for Mr. Hoyer says his PAC is one of the most efficient, having given away $1.1 million of the $1.9 million it has raised so far this year.

Sen. Bob Menendez, the New Jersey Democrat facing a tough re-election battle, dined a dozen times over the past two years at Morton's. The bills, which totaled $3,197, were paid by his PAC. A spokesman for Mr. Menendez says the bills were either "fund-raisers for the PAC or donor prospecting."

The leadership PAC of Rep. Joe Barton, a Texas Republican, paid $5,000 to the Blessing Funeral Home in Mansfield, Texas, for a funeral in June 2004. Larry Neal, an aide to Mr. Barton, said the funeral expense was for "the burial of a young staff assistant in Texas who left behind a devastated widow and their one-year-old child after committing suicide at home one awful summer night."

Republican Rep. Mike Oxley of Ohio, who is retiring, paid for $30,000 worth of going-away parties for himself from his leadership PAC. His spokeswoman declines to comment.

Several lawmakers have family members on the payrolls of their leadership PACs. Mr. DeLay's wife, Christine, was paid more than $170,000 by his PAC over the last four years for fund raising and political consulting. His lawyer says the payments were appropriate. The wife of California Republican Rep. John Doolittle worked as a fund-raiser for his PAC, keeping 15 percent of the contributions she brought in as payment. And California Democratic Sen. Barbara Boxer's PAC is run by her son, a lawyer, who has been paid $80,000 so far this election cycle.

The PACs can remain in place even after lawmakers retire. In September 2004, New York Rep. Jack Quinn started a leadership PAC a few months before his planned retirement from the House. Mr. Quinn said the account would allow him to donate leftover campaign funds to other Republican candidates. Since then, he has donated about $100,000 to candidates and has used another $115,000 to pay for expenses ranging from liquor for a Christmas party with political allies to insurance on a 2004 Ford Taurus he once used as a campaign vehicle.

Mr. Reid, the Senate minority leader, travels frequently to Las Vegas to raise money and meet with political supporters. Many of his bills there are paid by his Searchlight Leadership PAC, named after his hometown in Nevada. In June, for example, his PAC paid $3,800 for hotels and fund-raisers at Caesars, Mandalay Bay and the MGM Grand. In August, it paid another $660 for meals and hotels during a pair of Las Vegas trips.

Jim Manley, a spokesman for Mr. Reid, says the expenditures are legal and appropriate. Some of them, he says, cover costs incurred by the minority leader's staffers, since Mr. Reid often stays at his home about 50 miles outside the city. "These expenditures are not especially large by Las Vegas standards," he says.

The Searchlight PAC was set up to support Democratic candidates, he says, and all its expenses "are directly related to fund raising, donor prospecting and donor maintenance, activities that are the core of the fund's permissible activities."

During the 2006 election cycle, Mr. Reid's PAC raised $2.2 million and distributed $447,000 to Democratic candidates and political parties, or about 21 cents of every $1 it raised, according to PoliticalMoneyLine. For the 2002 election, it raised $1.1 million and contributed $350,000 to candidates. During that election cycle, it spent about $14,000 on salaries, overhead and other expenses. Through Oct. 18 of this cycle, it has spent $1.2 million.

"There's no mystery about why the leadership fund is spending more money," Mr. Manley says. "It is the right way for a Senate leader to help elect other Democrats consistent with federal election law." He added that Mr. Reid also has contributed $845,000 to Democratic candidates and political parties from his separate re-election account.

Between December 2005 and March 2006, Mr. Reid's PAC paid $3,367 to cover stays by his guests at the Ritz-Carlton in Georgetown, where Mr. Reid has a condominium. Over the past two years, it paid another $3,000 for meals and to set up meetings at the hotel. Mr. Manley says the expenditures in Washington were for fund-raising events or for feeding and lodging "special guests" who attend them.

The PAC also spent $21,000 on gifts for political supporters, including $3,082 for bracelets and cuff links, $1,000 for art, $1,592 for chocolates, $803 for a pair of iPods, and hundreds of dollars for merchandise at Barnes & Noble and Amazon.com. "These types of expenses are a normal part of every fund-raising operation," says Mr. Manley. "They are designed to thank donors for their past efforts and to strengthen their future commitment to helping to elect Democrats."