WASHINGTON (AP): With economic issues taking center stage in the presidential election, Republican John McCain fought back against attacks by Barack Obama by arguing that his Democratic opponent's trade and tax policies would only worsen the faltering U.S. economy.

Obama is focusing the first full week of his general election bid for the White House on the U.S. economic crisis, mining a deep vein of anxiety among voters. The most recent Gallup Poll shows 78 percent of Americans hold a negative view of the nation's economy.

Obama blames the administration of President George W. Bush for the U.S. economic woes and claims McCain would promote similar policies.

The sharp economic downturn has given Obama a particularly potent political whip in his battle against McCain, especially given that the Iraq war _ once expected to be the predominant issue _ is no longer the pressing issue in the minds of most voters.

Given those realities, Obama is shifting attention to the economy and away from national security and foreign policy _ issues where McCain feels stronger given his more than 20 years of experience in the Senate.

Voter fears of falling living standards were compounded in recent days by news that unemployment jumped to 5.5 percent last month even as the nationwide price for gasoline continued surging past $4 a gallon for the first time. The price is still low for Europeans and others, but it is a shock for Americans used to cheap gas.

Before his fellow Democrats failed to force a vote on taxing oil companies on Tuesday, Obama was already on the record for raising corporate oil taxes if elected. McCain would reduce their taxes as an incentive for increasing production.

McCain's fellow Senate Republicans blocked a move by Democrats to impose a windfall profit tax on American oil giants, a vote likely to play into Obama's hands.

The failed Senate proposal would have taxed ``unreasonable'' profits of the five largest U.S. oil companies. Republicans argued that raising taxes on the oil industry would not solve U.S. energy problems.

Under the Obama blitz on the economy, McCain fought back on Tuesday, charging that his opponent's economic plans would raise taxes and further shrink the American job pool.

A day after Obama hammered him on the economy, McCain told small business owners that Obama, a first-term Illinois senator, would boost their tax burden and cause higher operating costs.

``You work hard in small businesses to grow and create new jobs and opportunities for others,'' McCain told a Washington gathering of the National Federation of Independent Business. ``The federal government shouldn't make your work any harder.''

He also criticized Obama for pledging to renegotiate the 1994 North American Free Trade Agreement with Canada and Mexico, which is credited with record exports by Republicans but blamed by many Democrats for job.

Later, however, McCain indicated that, like Obama, he could be open to a new economic stimulus package. Obama has proposed an additional $50 billion in relief on top of the $168 billion package approved this year. McCain also told a group of major contributors gathered in New York that he was prepared to consider extending jobless benefits, a position the Bush administration opposes. He did not give a dollar figure for the stimulus.

McCain has been shoring up his anti-tax credentials, pushing to extend Bush's tax cuts, which are set to expire beginning in 2010. Some party conservatives remain suspicious of McCain because he originally opposed the Bush tax cuts, arguing the cuts favored the wealthy and that there should be no tax cuts until the Iraq war costs were known. Now he argues that allowing the tax cuts to expire would amount to raising taxes, which he opposes.

Speaking later to reporters in St. Louis, Missouri, Obama called McCain's remarks misleading. He said he wants tax cuts that would benefit small businesses ``that are the backbone of our economy.'' His income tax plans, Obama said, would cut taxes for 95 percent of U.S. workers, while rolling back the Bush administration's tax reductions for the highest-earning 5 percent of Americans.

Obama has taken his economic message this week to states that have voted for Republicans in recent elections, but by margins slim enough that Democrats hope for upset victories this year or at least to force Republicans to fight for them. The general election is a series of state-by-state, winner-take-all contests.

According to the most recent Gallup Poll tracking survey, Obama leads McCain nationally by 7 percentage points, 48-41. It is Obama's first statistically significant lead since the poll began tracking his standing against McCain in March.

The Obama bump was seen to be at least partly a result of rival Democrat Hillary Rodham Clinton pulling out of the race on Sunday and throwing her considerable support behind her Senate colleague.

Obama's strategy also involves making inroads with evangelical voters who overwhelmingly supported Bush in the last two elections but are less enthusiastic about McCain.

On Tuesday, Obama discussed Darfur, the Iraq war, gay rights, abortion and other issues at a private meeting with about 30 Christian leaders at a law firm's office in Chicago.

Bishop T.D. Jakes, a prominent black clergyman who heads a Dallas megachurch, said Obama took questions, listened to participants and discussed his ``personal journey of faith.''

Jakes said the meeting seemed designed to prompt a wide discussion rather than to result in commitments from either Obama or those attending.

Obama, meanwhile, has been scouring the field for a running mate, sending his vice presidential vetting team to Washington to consult with top Democrats in Congress.

Sen. Kent Conrad, who met with Obama's team Tuesday, says the candidate is considering picking his running mate from among former top military leaders. Such a move would balance the military bonafides of the Republican ticket led by McCain, who was a naval aviator during the Vietnam War and spent more than five years as a prisoner of war in North Vietnam. Obama has not served in the military.

Obama's team discussed roughly 20 names as possible vice presidential candidates with Conrad, who would not disclose any of them.

One name being discussed is retired Gen. James Jones, the former NATO Supreme Allied Commander, according to a person familiar with the process.