McCain versus Obama on 4 key issues

Mortgage crisis

The candidates' different tacks were in evidence as the home mortgage crisis ballooned. Obama offered a plan that included aggressive regulation of financial institutions, relief for homeowners and a $30 billion economic stimulus package.

McCain initially criticized Obama's plan as a "multibillion-dollar bailout for big banks and speculators."

"There is a tendency for liberals to seek big government programs that sock it to American taxpayers while failing to solve the very real problems we face," McCain said.

Then, McCain faced a barrage of criticism for downplaying a government role in responding to the crisis. Two weeks later, he changed his tone and proposed spending up to $10 billion for government-backed mortgages to "deserving" homeowners facing foreclosure.

Health care

On health care, Obama leans hard on government action to make insurance more affordable and, ultimately, universally available. He would make coverage mandatory for children, expand federal subsidies for the uninsured and impose new funding requirements on employers.

McCain, in his health plan, shuns that infusion of government money and authority and instead relies on market competition to drive down costs. He would establish new tax incentives for individuals to get their own health insurance and reduce the incentives for people to get insurance through their employers.

Global warming

McCain has called for mandated emissions limits to curb global warming, an example of him embracing government regulation and parting ways with most fellow Republicans.

But he opposes most government incentives and subsidies to help meet those emissions limits, and which are favored by Obama and many other officials. Obama, for example, would invest $150 billion in subsidies over 10 years to develop alternative fuels.

McCain, discussing environmental issues last month, told voters in Washington state, "I'm a little wary -- I have to give you straight talk -- about government subsidies. When the government jumps in and distorts the market, then there's unintended consequences as well as intended."

He seems to make an exception for subsidies for nuclear power. McCain opposed a global warming bill before the Senate this month because it did not include enough government aid for developing nuclear energy.

Tax policy

The candidates' differences on tax policy are especially stark.

McCain wants to extend Bush's signature income tax cuts, which are due to expire after 2010; Obama wants to let the tax cuts for upper-income people lapse. McCain wants to cut corporate tax rates and eliminate the alternative minimum tax; Obama's tax relief plan is targeted on middle-income people.

Candidates' risks

Each candidate's approach to the economy carries risks.

The risk for McCain is that his laissez-faire approach will be out of step with anxious voters. That seemed to be the case when he initially downplayed the need for government action in response to the mortgage crisis.

The risk for Obama is that some of his policies, such as his call for raising taxes on upper-income people while cutting them for the middle class, will be rejected by swing voters who might be wary of a redistribution of wealth.