ASHINGTON, Dec. 6 - The Ohio secretary of state officially certified on Monday that President Bush won that swing state by roughly 119,000 votes, but an array of Democrats, third-party candidates and independent groups continued to question the results, issuing new demands for a statewide recount and a formal investigation of the vote.
Even before Secretary of State J. Kenneth Blackwell, a Republican, issued the final tally, the Democratic National Committee said it would appoint an expert panel to review voting problems in Ohio - including long lines, voting machine errors and understaffed polling stations - that it said had disenfranchised voters in predominantly Democratic urban districts.
Democratic officials, walking a fine line between their angry liberal base and centrist voters who consider the election over, said they were not contesting the results. But they said they planned to use the results of their investigation, which is to be completed by the summer, to demand changes to the electoral systems in Ohio and other states.
"Like Florida in 2000, which gave us a lot of information and evidence that we used later on to improve our election system, Ohio will play that role for us this year," said Donna Brazile, chairwoman of the Democratic National Committee's Voting Rights Institute. "There's no question that there's been a long pattern, a chilling pattern, of voter intimidation, voter suppression across the country over the years."
Lawyers for the Green Party and the Libertarian Party - supported by Senator John Kerry's presidential campaign - are also expected to file requests on Tuesday in each of Ohio's 88 counties seeking a recount, a process that could take several weeks. The Kerry camp said it was not challenging the outcome of the contest but wanted to make sure all votes were counted.
And on Wednesday, lawyers from the Alliance for Democracy, a group based in Massachusetts that advocates fair elections, plan to ask the Ohio Supreme Court to throw out the election results and declare Mr. Kerry the winner. Officials with the group, which is filing the request on behalf of 25 Ohio voters, said they would be able to demonstrate widespread irregularities and fraud in the heavily Republican counties surrounding Cincinnati.
"We will allege in the complaint that the result should have been Kerry winning," said Clifford Arnebeck, a lawyer in Columbus, Ohio, who is co-chairman of the alliance.
Carlo LoParo, a spokesman for Mr. Blackwell, said Ohio's voting system was one of the fairest in the nation because each county board of elections includes two Democrats and two Republicans. "People would be alleging a conspiracy of both Republicans and Democrats to commit fraud," Mr. LoParo said.
Mr. Blackwell himself, who oversees the state's voting system, has been severely criticized by Democrats as making decisions that benefited Mr. Bush.
The new maneuvering comes 34 days after Mr. Kerry conceded Ohio and its 20 electoral votes to Mr. Bush, allowing the president to declare victory nationwide. At the time, Mr. Bush was leading Mr. Kerry by about 136,000 votes in Ohio, a margin Mr. Kerry's aides considered insurmountable.
The final vote count showed that the margin had shrunk to 118,775 votes, or 2 percent of the total, after absentee and provisional ballots were tabulated and some Election Day counting errors were corrected, according to the certified results released by Mr. Blackwell on Monday.
The voting in Ohio occurred under the scrutiny of squadrons of lawyers and volunteer monitors from the two major parties and several independent groups, which documented problems with long lines, errant voting machines and confused election officials.
Republicans have asserted that while there were some problems, Ohio's election was generally smooth. Asked to comment about the Democrats' calls for an investigation in Ohio, Scott McClellan, a White House spokesman, called the election there "free and fair."
"The American people spoke very clearly on Nov. 2," Mr. McClellan said on Monday. "It was a clear victory for the president of the United States."
Still, many Democrats and members of third parties around the country share a perception that the Ohio election was riddled with technical problems and fraud. The anger with the results has fueled successful fund-raising drives by groups that contend widespread irregularities occurred.
The Ohio Green Party and Libertarian Party said they had raised more than $250,000 to defray the cost of recounting ballots in all 88 counties. And the Alliance for Democracy raised $108,000 through its Web site for the recount effort, Mr. Arnebeck said.
Under Ohio law, the recount must begin within 10 days of the formal request and groups calling for a recount have to pay for part of the cost.
Ohio's presidential electors are scheduled to meet next Monday to cast their votes for Mr. Bush, though it is virtually certain that the challenges and recounts will not be completed by then.
James Dao reported from Washington for this article, and Albert Salvato from Cincinnati.