SCENARIOS: Financial crisis threatens Obama, McCain proposals

PHOENIX (Reuters) - Presidential candidates Barack Obama and John McCain have both made expensive promises that may be hard to fulfill from the White House with resources strangled by the U.S. financial crisis.

Below are some of the proposals that could be affected as well as responses from the candidates about potential changes:

OBAMA

Health care: The Democratic senator from Illinois has promised a major overhaul of the U.S. health insurance system that his campaign estimates will cost $50 billion to $65 billion. He promises to pay for that by rolling back tax cuts on Americans making more than $250,000 a year. The crisis on Wall Street could divert attention from that goal.

Energy: Obama said during the first presidential debate the crisis could affect parts of his plans to revamp U.S. energy policy and invest in renewable sources of fuel such as wind and solar power.

Foreign aid: Obama's running mate Joe Biden said the crisis could slow down efforts to double foreign aid.

Response: Other than the potential changes mentioned above, Obama is sticking with his campaign promises.

MCCAIN

Taxes: The Republican senator from Arizona has promised to keep the tax cuts put in place by President George W. Bush and reduce corporate income tax rates to 25 percent from 35 percent. His tax plans have been estimated to cost some $400 billion a year, according to the Wall Street Journal. The need for revenue to deal with the crisis could make that pledge less palatable.

Budget: McCain has pledged to reduce government spending and balance the federal budget by 2013. A shaky economy, exacerbated by the crisis, could make that impossible to achieve.

Response: McCain said in a recent interview with Reuters that the Wall Street crisis and bailout bill would not alter his campaign promises, saying Obama's proposals were more vulnerable because they require greater spending.

(Editing by David Wiessler)