HEMPSTEAD, New York, (AFP) - Republican John McCain and Democrat Barack Obama head into the final 19-day stretch of their presidential campaigns Thursday after a feisty final debate that snap polls say further cemented Obama's lead in the race. McCain aggressively and even angrily attacked Obama's policy ideas and goals during Wednesday night's debate in a bid to turn around his flagging campaign. But instant polls by television networks said voters were dismayed by the Republican's negative barrage, with Obama declared the decisive victor in the candidates' last scheduled face-to-face clash before the Nov 4 election. McCain, down a hefty 14 points in one poll as the United States weathers its worst financial crisis in decades, savaged Obama's ties to 1960s radical William Ayers and said his tax plans were nothing more than "class warfare." Keeping his composure, Obama in turn accused McCain of trying to distract voters on a day that New York's Dow Jones share index posted its second-biggest points fall ever on mounting fears of a crippling US recession. McCain, 72, said he did not care about "an old washed-up terrorist" like Ayers, once a bomb-throwing militant in the Weather Underground group who is now a Chicago professor of education. "But as Senator (Hillary) Clinton said in her debates with you, we need to know the full extent of the relationship with you," he said, glaring at Obama seated on the other side of a narrow table at New York's Hofstra University. McCain also assailed the liberal group ACORN, which is accused in several states of adding fraudulent names to pro-Obama voter registration lists, and chided Obama for persistently linking him to President George W Bush. "Senator Obama, I am not President Bush. If you wanted to run against President Bush, you should have run four years ago," McCain said, proclaiming his record of bucking the Republican line in contrast to Obama's inexperience. Obama, 47, accused McCain of wildly distorting the truth over both Ayers and ACORN, and said voters were turned off by the "100 percent negative" tone taken by the Republican's campaign at a time of rampant economic anxiety. Obama said he could be forgiven for mistaking McCain's policies for Bush's "because on the core economic issues that matter to the American people... you have been a vigorous supporter of President Bush." "I don't mind being attacked for the next three weeks," the Illinois senator added during one of several spirited clashes in the 90-minute debate, which also encompassed abortion, energy, health care and education. "What the American people can't afford, though, is four more years of failed economic policies and what they deserve over the next four weeks is that we talk about what is most pressing to them, the economic crisis." Both men appealed to "Joe the Plumber," or Toledo, Ohio resident Joe Wurzelbacher, who found instant fame when he bumped into Obama on Sunday during a round of door-to-door canvassing and expressed concern that Obama's tax plan would hit him hard. Obama hit back with his version of his chat with Joe. "What I essentially said to him was, five years ago, when you were in the position to buy your business, you needed a tax cut then. "And what I want to do is to make sure that the plumber, the nurse, the firefighter, the teacher, the young entrepreneur who doesn't yet have money, I want to give them a tax break now." McCain adviser Steve Schmidt, the architect of the Republican's get-tough strategy, insisted the Arizona senator had triumphed in the final debate. "Senator McCain did a very efficient job and won the debate on the economy tonight. It's clear to anyone who watched tonight that Senator Obama wants to spend our way into a depression," he told reporters. But the post-debate TV polls told a different story. In CNN's poll, 58 percent of respondents said Obama won the debate compared to 31 for McCain, with 70 percent saying Obama was more likeable. A CBS poll scored the debate 53-22 percent for the Democrat. "(McCain) looked frankly desperate, he looked angry, frankly he did not look presidential," Democratic Michigan Governor Jennifer Granholm said. A New York Times-CBS News poll late Tuesday had Obama ahead nationally by the huge margin of 14 points, 53 to 39 percent. CNN-Time polls showed Obama up five points among registered voters in Colorado, by eight in Florida, by three in Missouri and by 10 in Virginia " which has not voted for a Democratic presidential hopeful since 1964.