WASHINGTON A general-election race for the White House between Democrat Barack Obama and Republican John McCain would feature vastly different approaches on the thorniest political issues, from Iraq and diplomacy to taxes and health care.
Their recent sparring over Obama's willingness to speak to hostile foreign leaders was a warm-up for what could be a rancorous five-month run-up to November's election.
"It will be as clear a choice as there has been in a generation," said Doug Schoen, a Democratic consultant and former adviser to President Bill Clinton. "You've got two very different views of the world presented in stark relief."
Obama has almost clinched the Democratic presidential nomination over rival Sen. Hillary Clinton of New York and McCain has wrapped up the Republican nod. Both have focused on each other in recent weeks.
The contrasts between McCain, 71, a white former Navy pilot and Vietnam prisoner of war, and Obama, 46, a black Harvard Law School graduate and former community organizer, go far beyond the personal.
Their ideological gulf is most evident on two issues usually ranked in opinion polls as the top concerns of American voters -- the Iraq war and the faltering economy.
"On the two big-ticket issues, they couldn't be farther apart," said Dan Schnur, a California-based Republican consultant and a McCain aide during his 2000 presidential bid.
McCain was a prominent and ardent supporter of the decision to invade Iraq and vows to keep U.S. troops there until the war is won. He recently said 2013 was a reasonable date for achieving that goal and ending U.S. involvement.
Obama, an Illinois senator, was an early opponent of the war who has promised to remove U.S. combat troops from Iraq within 16 months of taking office.
The chasm is similar on taxes. McCain supports extending President George W. Bush's cuts and reducing corporate tax rates, while Obama would let Bush's cuts expire for wealthy Americans -- those making more than $250,000 annually -- and let the rate reductions on capital gains taxes expire, another item that normally affects primarily high-income earners.
McCain, an Arizona senator, opposed Bush's cuts when they were passed in 2001 and 2003 because he said they would increase the budget deficit and disproportionately favor the wealthy. He supports extending them now, saying they would offer help to a struggling economy.
The two already have clashed over Obama's opposition to McCain's idea of a summer holiday from the federal gasoline tax. Obama called it a political stunt that would provide little help, while McCain said the idea could give a slight boost to struggling families seeking a vacation.
Obama also would renegotiate the North American Free Trade Agreement, blamed by some Democrats and labor unions for costing U.S. jobs. McCain opposes amending the pact and says it has been beneficial.
HEALTH CARE SPLIT
The two candidates also have sharply different approaches to health-care reform, which consistently ranks as the second most important domestic issue after the economy in national opinion polls.
McCain would use tax credits to help shift from employer-based insurance coverage to an open market system where people can choose from competing policies.
Obama would keep the existing job-based system and expand government involvement. He supports universal health coverage for the 47 million Americans without insurance, although he would only require coverage for children.
Health care, however, has not been a key factor in a presidential election since the collapse of the Hillary Clinton-led reform effort in 1994 when she was first lady, and both candidates have emphasized other items.
McCain has repeatedly hammered Obama's lack of national security experience, criticizing his willingness to talk to leaders of hostile nations without preconditions as a sign of naiveté.
Obama blasts McCain's economic leadership and his ties to Washington lobbyists, saying the Republican's presidency would amount to Bush's third term. Obama, who says McCain would prolong Bush's failed diplomatic approach, portrays the election as a choice between the future and the past.
Pollster John Zogby said every link drawn between the unpopular Bush and McCain would be a plus for Obama.
"Anything that reminds people of Bush hurts McCain, at least until he decides to step away from him and become a maverick again," Zogby said.
McCain has taken stances that put him at odds with many members of his party. His support for an overhaul of immigration laws angered some conservatives, although he softened his approach during the battle for the nomination.
Unlike Bush, McCain has addressed global warming as a legitimate problem and supports federal spending on stem-cell research.
"McCain has a chance to muddy up the differences on a few issues that have been politically helpful to Democrats in recent election cycles," Schnur said.
(Editing by Jackie Frank)
(To read more about the U.S. political campaign, visit Reuters "Tales from the Trail: 2008" online at blogs.reuters.com/trail08/ )