The main challenge facing presidential hopefuls John McCain, Barack Obama and Hillary Clinton is to convince voters that they understand the needs of average Americans. Yet the more voters get to know them, the clearer it becomes that they lead lives that are far from ordinary.

McCain, Obama and Clinton all have prevailed against daunting odds to be among the most powerful people in the country. Their success has also made them celebrities and they have made tidy sums of money writing best-selling books. They have received a slew of awards from their many admirers and have been both lampooned and cheered as guests on "Saturday Night Live."

To understand what these presidential contenders will do if elected, voters need to first examine their respective political records. But we can also glean insights from taking a look at the personal experiences and individual choices these three remarkable people have made:

Income tax information is generally private, but in the case of presidential candidates, it's not. Their invasion of privacy makes for hours of fun for those of us interested in how much money others make. Here's how the numbers shook out for 2007 tax returns:

John McCain:
Adjusted gross income $386,527
Charitable contributions $105,467
Federal income tax $118,660
Actual tax return here (large file).

Other interesting information: McCain gave $105,467 to charity, which was 27% of his income. He also made just over $110,000 from books he's written.