Supporters of the sweeping measure to reduce the role of money in politics, gaining momentum from the scandal over the collapse of big-time political donor Enron, said they had picked up the necessary 218 signatures to force a vote.
Reps. Corrine Brown of Florida and Richard Neal of Massachusetts, both Democrats, were the last two signatures needed on the Democrat-sponsored petition.
"After everything that happened with Enron, we've got to take money out of the system of elections," Brown told reporters immediately after signing the petition.
"The American people deserve a full debate about how campaigns are financed," said Neal.
Earlier on Thursday, Republicans Charles Bass of New Hampshire and Thomas Petri of Wisconsin bucked their leadership to become the 215th and 216th signatures on the petition.
In all, 197 Democrats signed the petition, joined by 20 Republicans and one independent.
The bill gained new life in recent weeks from the lobbying and campaign donations of fallen energy-trading giant Enron Corp., which lavished nearly $6 million on politicians since 1989. They said the growing scandal over the company's fall provided a perfect illustration of how campaign money wins friends and influence in Washington.
"If you can look at the Enron case and not see the influence that soft money can buy through this process, you're blind," Rep. Zach Wamp, a Tennessee Republican, told reporters before the final signatures were gained.
Under House rules, supporters of the measure to ban unregulated and unlimited "soft-money" donations to political parties and put new restrictions on broadcast attack ads can try to bring up the issue for the first of several test votes after seven working days.
The two parties raised nearly $500 million in soft money in the two-year period that ended on Dec. 31, 2000, and have continued to collect donations measured in the millions of dollars in the current election cycle.
The Senate passed its version of the campaign finance bill last April but supporters in the House, where the bill passed in 1998 and 1999, rejected the rules of debate set by House leaders in July.
The developments in the House occurred as White House spokesman Ari Fleischer was briefing reporters.
"The president has made it very clear to Congress that they cannot count on him to veto campaign-finance reform," he said. "The president is committed to having campaign-finance reform enacted into law. He believes improvements can be made in the current system of campaign financing."
House Speaker Dennis Hastert and other Republican leaders, who oppose the measure, had refused to reschedule debate.
House Republican leader Dick Armey indicated Wednesday that the leaders would agree to a debate in an "expeditious and codial" fashion once the signatures were acquired.
The successful petition grants a vote on the leading campaign finance measure sponsored by Reps. Marty Meehan of Massachusetts, a Democrat, and Christopher Shays of Connecticut, a Republican, and two alternative proposals, including one submitted by House Republican leaders.
The leading vote-getter of those three proposals would face up to 20 amendments during 11 hours of debate over two days.
"While I'm cautiously optimistic about the prospects for success, I don't underestimate the determination of opponents of reform," said Arizona Republican Sen. John McCain, co-sponsor of the Senate version with Wisconsin Democratic Sen. Russell Feingold.
The House petition drive had stalled short of the needed 218 signatures after the Sept. 11 attacks, but supporters said questions about the efforts of big-money donor Enron to reach out to the Bush administration for help and to influence its energy policy helped resurrect the issue.
"Enron is a case in point - the big money and the big-money interests sit in the front row, and the average person sits in the back, and that needs to be changed," said Kentucky Democratic Rep. Ken Lucas.
Nearly $3.6 million of the Enron contributions were soft-money donations that would be banned under the Shays-Meehan legislation.
Delaware Republican Rep. Michael Castle likened the years-long battle to overhaul campaign finance laws as a see-saw, and described Enron as "a 200-pounder who has just gotten on."
He said approval of the Shays-Meehan measure was almost a foregone conclusion.
"The passage of this legislation in the House of Representatives is close to over as a result of what has happened here," Castle said.
While nearly three-quarters of the donations went to Republicans, lawmakers from both parties have scrambled to distance themselves from the company while all four of the congressional campaign committees are returning their Enron contributions.
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