Just days before becoming president, Barack Obama was looking to Congress on Wednesday for important votes that will shape the early days of his administration, as lawmakers hash out an economic rescue package and vet his Cabinet picks. Obama's goal of having his Cabinet up and running shortly after he takes office Tuesday has hit a new snag, as it became apparent that a key member of his economic team would not receive a quick stamp of approval from Congress. Questions about Treasury Secretary-designate Timothy Geithner's failure to pay $34,000 in taxes several years ago have pushed back his confirmation hearings by at least a week. On the economy, Obama got tough with senators in a meeting Tuesday, promising, the lawmakers said, to veto any attempt to block the next administration's access to the second half of the $700 billion bailout package designed to prop up the country's wobbly financial system. Obama also is pushing for an additional $800 billion economic stimulus plan. Use of the first $350 billion from the huge fund, conceived in the face of a near financial collapse in September, has drawn heavy criticism from the public and Congress for a disproportionate focus on big financial institutions to the detriment of homeowners facing home mortgage foreclosure and smaller institutions and businesses. Obama has broken with protocol observed by most of his predecessors who largely stayed out of the public eye until taking office, arguing that the economic perils facing the United States require that he and Congress must be ready to move vigorously as soon as he is inaugurated. The largely smooth transition toward Obama's assuming office as the 44th president hit an embarrassing bump Tuesday when Geithner owned up in a closed door session with senators to failing to pay $34,000 in taxes from 2001 to 2004. The oversight has been corrected but complicated the confirmation of the highly respected choice for treasury secretary. The tax revelations derailed Senate Democrats' plans Wednesday to speed him to confirmation as treasury secretary so he could be sworn in on Inauguration Day. Now, Geithner's confirmation hearing isn't scheduled until next Wednesday, with Senate debate and a vote some time after that. The Senate's No. 2 Republican, Sen. Jon Kyl, objected to a hearing this Friday for Geithner at the Senate Finance Committee. Kyl is insisting on rules that require a full week's notice for scheduling such a session, according to an aide close to the confirmation process. His objection was disclosed on condition of anonymity because the aide was not authorized to announce it. Still, Democrats and Republicans on the panel voiced strong support for Geithner, who was phoning senators individually to persuade them that his tax problems were the result of innocent mistakes, not deliberate attempts to avoid paying the Internal Revenue Service, the U.S. tax agency. Obama has stood by Geithner. White House spokesman Robert Gibbs in a statement said Geithner merely "made a common mistake on his taxes." Geithner failed to pay self-employment taxes for money he earned from 2001 to 2004 while working for the International Monetary Fund, according to materials released by the committee Tuesday. The panel's report also noted that Geithner briefly employed a housekeeper in 2005 whose legal immigrant work status had lapsed. Gibbs said Geithner "was unaware that his part-time housekeeper's work authorization expired for the last three months of her employment." Immigration issues have derailed presidential nominations in the past. Geithner is the second Obama nominee to face controversy. New Mexico Gov. Bill Richardson withdrew his name on Jan. 4 as Obama's Commerce secretary after questions surfaced about an ongoing federal investigation into how political donors landed a lucrative transportation contract. However, Hillary Rodham Clinton, Obama's choice as secretary of state, was sailing through her confirmation process with collegial questioning Tuesday by the Senate Foreign Relations Committee. Her confirmation is not in doubt, and she could be on the job as soon as Obama's first full day in office. The Senate Foreign Relations Committee planned to vote on the selection Thursday. On Wednesday afternoon, Obama and Vice President-elect Joe Biden plan a preinaugural visit to the Supreme Court at the invitation of Chief Justice John Roberts. It's something of a tradition for incoming presidents and vice presidents to pay their respects to the court. The Obama team said Wednesday's visit was private and reporters would be excluded. In another courtesy call, Obama on Tuesday night dined with some of his critics in the news media at the home of conservative columnist George Will in a Maryland suburb, according to a report of the press pool that travels with the president-elect. Obama's transition office did not say what the president-elect and the conservative writers discussed. ___ Associated Press writer Julie Hirschfeld Davis contributed to this report.