Republican Sen. John McCain has a chance to win the presidency, especially if there is a geopolitical crisis. He has many obstacles to overcome — his age, President Bush’s unpopularity and the weak economy — yet questions also persist about whether someone as untested as Obama is up to the job.

But voters want a change and McCain has an uphill battle. Regardless of the turmoil at the top, 2008 could be a strong year for the Democrats overall; they are poised to gain several more seats in the Senate and House, extending their majorities.

Despite dramatic rate cuts and innovative new lending policies by the Federal Reserve Bank, the economy has not yet recovered and credit markets are not yet near normal. It could be early spring before the U.S. economy shows strong signs of life, which could be the biggest reason why McCain faces an uphill battle to win the presidency.

While McCain would differ from the current president in a few key areas, a McCain presidency would likely have a fair amount of continuity with existing Bush administration policies. With Obama in the White House, we could see significant changes in a variety of sectors.