President Bush has invited bloggers to join him today as he signs into law a bill creating a database of federal spending -- a recognition of their role in forcing the bill through Congress over the objections of senior senators and an indication of how much bloggers are changing the political process.

A coalition of bloggers from the left and the right last month did what the Senate's Republican leadership could not: smoke out obstructing senators, bring public pressure to break their hold and move the bill to the Senate floor, where it passed by a voice vote.

"The bloggers mobilized Congress; Congress did not mobilize bloggers," said John Hart, spokesman for Sen. Tom Coburn, the Oklahoma Republican who teamed with Sen. Barack Obama, Illinois Democrat, to support the bill.

"It really does represent a revival of basic democratic values: that active citizens using tools of technology really can steer the political process," Mr. Hart said. "And what happened was profoundly subversive to the established political order."

The legislation will establish a searchable database of all federal contracts and grants, and most other spending.

The Bush administration supported the database as a way to improve transparency and accountability, but senior senators from both parties blocked the bill through a "secret hold," a parliamentary tradition that allows a single senator to obstruct legislation.

Bloggers mounted a drive to identify the obstructors, asking readers to call their senators and demand to know whether they were the culprits. The obstructors eventually acknowledged their role and relented.

One administration official called the bill the "'Blair Witch Project' version of legislation" because support grew by word of mouth through blogs.

Bill-signing ceremonies give the president, lawmakers and key interest groups a chance to proclaim victory. Bloggers say this is the first time they have been invited as a group.

"There's no doubt in my mind that without the attention paid to the bill by the bloggers it wouldn't be getting signed into law by the president," said Tommy Vietor, a spokesman for Mr. Obama.

"It was a bill that just made so much intuitive sense that no one could understand how Congress could not pass it, which got folks involved and brought a lot of pressure from bloggers on the right and left."

Some of the bloggers also will have a chance to talk about their work on the bill tomorrow with Clay Johnson, deputy director for management at the Office of Management and Budget.

"They definitely showed a tremendous interest and a dogged determination to see this bill passed, and we are happy to invite them to the White House," said White House spokeswoman Dana Perino.

Glenn Reynolds, who led the charge from the right on his blogs Instapundit.com and Porkbusters.org, said blogs have given a voice to the constituency that wants spending controls and accountability. That means lawmakers can't talk about financial responsibility while getting away with profligate spending on pet projects.

"That's sort of the big news here," Mr. Reynolds said. "What blogs make it hard for people to do in a whole lot of different ways is tell one group of people one thing and tell another group something different, and hope nobody noticed."

Part of the bill's success may be attributed to the unlikely team of Mr. Coburn and Mr. Obama. They first collaborated on good-government efforts over Hurricane Katrina relief spending, and their cooperation on spending issues could be the model for finding agreement on entitlement relief.