In a new line of attack, top Democrats are arguing that Mitt Romney and the Republicans, with their focus on spending cuts, are following Europe’s austerity-first example, to dismal effect so far: Greece over the edge; Italy, Spain, Portugal on the edge; Britain in recession; and the United States suffering through a needlessly weak recovery because of government cuts. Former President Bill Clinton offered the clearest version of the case on Monday night, when, introducing Mr. Obama at a fund-raiser in New York, he listed the steps that Mr. Obama had taken to spur the economy, and then asked: “Why aren’t things roaring along now? Because Europe is in trouble and because the Republican Congress has adopted the European economic policy.” Mr. Clinton added, “Who would have thought, after years and years, even decades, in which the Republican right attacked ‘old Europe,’ that they would embrace the economic policies of the euro zone — austerity and unemployment now at all costs.” Mr. Obama has so far declined to take up the line of attack himself, in part, administration officials say, because it would be unseemly for him to do so when he is trying to persuade European leaders to move away from austerity and deal more aggressively with their financial crisis. But plenty of administration officials, Obama advisers and campaign surrogates have been quick to take up the argument, making a case that had previously been relegated to liberal writers instead of Democrats. At a time when the American economy is looking weaker than it had seemed only a few weeks ago, the European analogy gives Democrats a story to tell about why the recovery has been slower than they had hoped. Romney campaign officials and other Republicans are not entirely unhappy about the new Democratic message, in part because it keeps the debate focused on Mr. Obama’s biggest weakness: the state of the economy. Mr. Romney’s aides respond that Europe is in bad shape all right, but that is because European leaders have not gone far enough on austerity. “Europe is facing some terrible choices because they postponed the effort to get their economic house in order,” said Kristen Silverberg, a United States ambassador to the European Union under President George W. Bush and now a Romney campaign official. “The United States still has the chance to correct course, but not if we sustain four more years of Obama-styled deficits.” The prime example for Democrats is the European country that has long seemed most similar to the United States — Britain — where Prime Minister David Cameron came into office in 2010 arguing that excessive spending by his Labor predecessors had spurred the country’s economic woes. Mr. Cameron, a conservative, slashed spending and eliminated hundreds of thousands of public sector jobs in a bid to reduce the deficit. Two years later, Britain’s Office for National Statistics says the country is experiencing a double-dip recession and is doing even worse than only a few months ago. “We have a laboratory experiment going on for what the Republicans want to do here, and that’s Europe,” said Senator Charles E. Schumer, Democrat of New York. “Particularly England, because they had the equivalent of a Democratic government, and Cameron comes in with austerity, and now they’re in a recession.” Mr. Obama, Mr. Schumer said, “can point to England as what could happen if the Republicans win.” Since the depth of the economic crisis in 2009, the United States, which has put a bigger emphasis on stimulus than Europe, has performed better than Europe, after the two had suffered similarly from the start of crisis in 2007 until 2009. Over all, gross domestic product in the United States was 3 percent higher in the first three months of this year than in late 2007, according to Haver Analytics, while gross domestic product in both the 17 countries of the euro zone and in Britain was still slightly smaller than at the end of 2007. “Europe has failed trying to do austerity,” said Representative Norm Dicks, Democrat of Washington. “They took the austerity approach, and that’s not how you get out of recession. Even Franklin Roosevelt learned that — we didn’t get out of the Great Depression until World War II.” Obama advisers argue that the budget proposal of Representative Paul D. Ryan, Republican of Wisconsin, which Mr. Romney has called “marvelous,” is actually a radical vision that would deepen the inequality in American society. They say that Mr. Ryan’s call for overhauling Medicare could drive up costs for future retirees and fundamentally change the popular health plan. “The Republican budget approach is far more extreme than austerity measures considered in Europe, in terms of both underlying goals and specific short-run policies, and the lack of any balance in approach,” said Jason Furman, principal deputy director of the National Economic Council. “Republican plans in Congress would be even more detrimental to longer-term growth because their refusal to consider any revenues necessitates even deeper spending cuts. In contrast, even conservative governments abroad have taken a more balanced approach to deficit reduction.” Mr. Romney recently gave the Democrats some ammunition when he appeared to acknowledge the connection between spending cuts and recessions in an interview with Time magazine, saying that he would not make too many cuts in his first year as president. “If you take a trillion dollars, for instance, out of the first year of the federal budget, that would shrink G.D.P. over 5 percent,” Mr. Romney said. “That is, by definition, throwing us into recession or depression. So I’m not going to do that, of course.” Still, his campaign and Congressional Republicans remain comfortable making an economic argument that revolves largely around spending cuts. Polls show that many Americans are skeptical that the Obama stimulus made a big economic difference.