On a pair of 99-0 votes, the Senate voted to expand the reach of the investigation and appropriate $4.35 million to cover its costs. Sen. Christopher Dodd (D-Conn.) voted present on both votes, citing his co-chairmanship of the Democratic National Committee the past two years.
The change came after Republicans suddenly found themselves short of votes - and concerned that their original scope would have prevented an investigation of White House coffees and sleepovers for big donors.
It also might have precluded investigating the $50,000 campaign donation that a California businessman brought to the White House and handed to Margaret Williams - chief of staff to Hillary Rodham Clinton.
Democrats had been pushing for inclusion of "soft money" - unlimited, party-building donations by corporations, unions and wealthy individuals - because Republicans collect more of it. For the 1996 election cycle, Republicans took in $141 million in soft money while Democrats raised $122 million.
Republican leaders had crafted language that would have allowed the Governmental Affairs Committee to investigate only illegal activities surrounding the 1996 elections.
This would have left out soft money, because these donations are not against the law. When Republicans agreed to include "improper" activities, the resolution passed, 99-0.
Sen. John McCain (R-Ariz.) said he was among the Republicans - as many as eight - who argued in a private lunchtime caucus against the original GOP plan.
"If you said, 'Maggie Williams, you come over and testify,' they say 'No, that's not illegal,"' McCain said. "It may be improper but it's not illegal."
Senate Majority Leader Trent Lott, (R-Miss.), said there were arguments in the caucus that "some of these coffees, some of these sleepovers" at the White House might have fallen outside the scope of the investigation.
Lott said the fight over the investigation should have been settled weeks ago, and blamed himself and Democratic leaders for letting it linger on.
Despite the inclusion of the big donor "soft money" in the investigation, Lott added, "I don't think that will be the main focus."
He predicted that the committee instead will concentrate on foreign money donated to U.S. campaigns and its influence.
Sen. Olympia Snowe, (R-Maine), who spoke for the expanded scope, said, "I just thought it would be very difficult for us to try to justify the position in which we weren't including the word 'improper."'
The solid Republican front began to crack earlier in the day, when Sen. Arlen Specter, (R-Pa.), said the Republican scope was too narrow and "filled with booby traps."
Until the Pennsylvania Republican's news conference, GOP senators stood together for an investigation confined to illegal activities in the 1996 presidential and congressional campaigns.
Senate Democrats are pushing for inclusion of activities that are considered improper though probably legal so the investigation can look at hundreds of millions of dollars in party-building "soft money" donations.
"I believe the public is going to respond badly to the current (Republican) resolution," Specter said. "There will be arguments as to what is legal and what is illegal."
Saying he also opposed the proposed Dec. 31 date for concluding the investigation, Specter said, "This resolution is filled with booby traps.
"There's no end to splitting the split hairs."
The key to Senate debate over the upcoming investigation is the role of "soft money" - a growing form of unlimited campaign giving by corporations, unions and wealthy individuals. The two major parties collected $263 million in 1996.
Republican leaders want the Rules Committee to look at these contributions, but Democrats object that the panel includes Republicans who oppose changing the soft money system.
"Foxes guarding hen houses is a good analogy," said Sen. John Glenn of Ohio, ranking Democrat on the Governmental Affairs Committee that will conduct the major Senate investigation.
One Rules Committee member, Republican Mitch McConnell of Kentucky, has said that in order to get rid of soft money, it would be necessary for the federal government to finance political campaigns.
Rules Committee Chairman John Warner, (R-Va.), insisted nonetheless that his panel would pursue soft money problems "with diligence."
In the House, Democrats accused Rep. Dan Burton, chairman of the Committee on Government Reform and Oversight, of planning "a partisan scope and budget" for his campaign financing probe.
Democrats on the committee requested a special meeting to protest the Indiana Republican's "unilateral authority" to release committee documents and issue subpoenas - and a scope that would investigate only Democratic fund raising.
The 20 committee Democrats, led by ranking Democrat Henry Waxman of California, wrote Burton that his proposal focuses "on the White House and the DNC (Democratic National Committee) and ignores fund-raising abuses in congressional campaigns."