WASHINGTON (AP) -- House Republican leaders scuttled a vote Thursday on a $51 billion budget-cut package in the face of a revolt by moderate lawmakers over cuts to Medicaid, food stamp and student loan programs.The episode marked a setback for Republicans on Capitol Hill. They had hoped to use the budget debate to burnish their deficit-cutting credentials with the public and their core political supporters, many of whom are disappointed with their party's performance on spending.The decision by GOP leaders came despite a big concession to moderates Wednesday, when the leaders dropped provisions to open the Arctic National Refuge to oil and gas exploration, as well as a plan letting states lift a moratorium on oil drilling off the Atlantic and Pacific coasts.But moderates countered that the spending cuts in the House budget plan were a separate issue from Arctic drilling. The cuts were too severe, moderates argued, especially when compared with a significantly milder Senate budget plan that passed last week.Democrats mounted a furious attack on the GOP budget plan for its cuts to social programs and pounded home the message that the overall GOP plan would increase the deficit when coupled with a subsequent tax cut bill."The Republican Congress is about to slash more than $50 billion from investments in our children's future in health care and education," said Rahm Emanuel of Illinois, chairman of the campaign arm for House Democrats. "And yet, because of Republican priorities, they are going to actually add $20 billion to our budget deficit. ... Only in a Republican Congress."Republican leaders said the postponement of the vote was simply a modest setback and that the budget effort would get back on track next week.Acting Majority Leader Roy Blunt said it was a "disappointing deadline to miss," but said the leadership was short a "handful" of votes and faced uncertainty about absenteeism as lawmakers looked ahead to a long Veterans Day weekend."We haven't done this in 10 years so the members aren't used to dealing with these mandatory programs," he said. "They're not used to pushing back when the other (Democratic) side suggests that the savings are deep cuts in social programs.""Democrats were united and made those issues too hot to handle for Republicans," said Minority Leader Nancy Pelosi, D-California.GOP leaders are willing to make more changes to the bill, Blunt said, but they risk a backlash from conservatives if the level of budget savings drops below a $50 billion figure promised by House Speaker Dennis Hastert, R-Illinois."I think we'll have the votes next week," Blunt said.Others are not so sure, noting that moderate opponents to the bill seemed unusually resolute.The overall bill is a Republican priority. The Senate last week passed a milder version to curb the automatic growth of federal spending by $35 billion through the end of the decade.The House plan cuts more deeply across a broader range of social services and targets more of the cuts at beneficiaries. Republican leaders say the effects will be modest to programs like the Medicaid health system for the poor and disabled. That system would still grow much faster than inflation even after beneficiaries face increased copayments and the likely loss of some benefits.The House convened Thursday and almost immediately went into a lengthy recess as GOP leaders including Blunt and Hastert worked to assemble support for the bill. In meetings with rank-and-file lawmakers, the leaders signaled a willingness to ease cuts to the Medicaid program.The development was also a setback for the reshuffled House leadership. Former Majority Leader Tom DeLay, R-Texas, was forced to step aside in September after his indictment on criminal conspiracy and money laundering charges. Blunt assumed the majority leader's post.Initial efforts by GOP leaders to shore up support for the bill by dropping the oil-drilling provisions won back roughly a dozen moderates, said Rep. Mark Kirk, R-Illinois. But other GOP moderates such as Mike Castle, R-Delaware, remained unconvinced. Castle said he met twice with Hastert on Thursday but the House's top leader had not secured his vote.White House press secretary Scott McClellan said Thursday the president was pleased that Congress was moving forward with deficit-reduction packages but that he still strongly supported opening a portion of the wildlife refuge to oil exploration.Copyright 2005 The Associated Press. All rights reserved.This material may not be published, broadcast, rewritten, or redistributed.