Washington ? President Bush quietly signed a landmark campaign finance bill Wednesday, documenting his misgivings despite analysts’ suggestions that he may benefit from the legislation more than anyone else.

How much of the law will take effect after the November election, as intended, remains to be seen. After Bush put pen to paper in the Oval Office, groups rushed to federal court to file suit on free speech grounds.

While banning “soft money” and restricting television ads, the bill also doubles the amount people can give directly to candidates for primaries and general elections, from $1,000 to $2,000.

Nearly 62,000 supporters gave Bush the maximum for his 2000 primary campaign. With that base of donors, he could start his re-election bid with a stake of at least $124 million. White House officials said Bush did not consider how the law might affect him.

“The president based this on the overall merits of what the legislation could do for democracy,” spokesman Ari Fleischer said.

While Bush criticized aspects of the bill in a “signing statement,” he told reporters that “it improves the system” overall.

“I wouldn’t have signed it if I was really unhappy with it,” Bush said.

Bush acted without fanfare or ceremony, signing the bill before leaving the White House for trips to South Carolina and Georgia to raise money for his Republican Party and for congressional candidates. He will be collecting some of the very type of contributions that will be restricted under the new law.

He will attend a fund-raiser today in Dallas for Republican Senate candidate John Cornyn.

“I’m not going to lay down my arms,” Bush said when asked about his plans to raise soft money this year. “I’m going to participate in the rules of the system.”

Supporters of the law applauded Bush, though some said his decision to forgo a formal ceremony disregarded reformers who have fought for years to pass the legislation. They include Sen. John McCain, R-Ariz., Bush’s rival during the 2000 presidential primary.

“The White House missed an opportunity to pay proper tribute to these members whose vision and persistence made this day possible,” said House Minority Leader Dick Gephardt, D-Mo.

McCain released a terse, one-line statement: “I’m pleased that President Bush has signed campaign finance reform legislation into law.”

As promised, two groups immediately went to court, the National Rifle Assn. and a coalition of critics led by Sen. Mitch McConnell, R-Ky.

“Today, I filed suit to defend the First Amendment right of all Americans to be able to fully participate in the political process,” said McConnell, who stalled the measure for years in the Senate. “And I look forward to being joined by a strong group of co-plaintiffs in the very near future.”