McCain and Obama have long, busy summers

Less conventional choices for Obama would be Republican Sen. Chuck Hagel of Nebraska, or a prominent Clinton supporter, such as Sen. Evan Bayh of Indiana. Virginia alone (a GOP-leaning state Obama would love to win) has three possible running mates: Gov. Tim Kaine, Sen. Jim Webb and former Gov. Mark Warner, who is running for the Senate.

McCain is likely to look at Republican Govs. Tim Pawlenty of Minnesota and Charlie Crist of Florida, two battleground states. Other possibilities include former Massachusetts governor and presidential rival Mitt Romney; Utah Gov. Jon Huntsman; South Carolina Gov. Mark Sanford; Alaska Gov. Sarah Palin; and former congressman and White House budget director Rob Portman of Ohio, another key state.

A private-sector choice might be Carly Fiorina, former chief executive of Hewlett-Packard.

3. Defining your opponent before he defines you.

Campaign pollsters say the average person still knows relatively little about Obama or McCain. Both men and their allies will race to fill in the blanks with appealing portraits of themselves and unflattering pictures of the other.

Obama's theme is "change," and he constantly says McCain would carry out "a third term" of President Bush, whose approval ratings approach historic lows. McCain portrays Obama as inexperienced, naive and more talk than action.

Youth and age will be a key subtext. Obama does not directly allude to McCain's age, which will hit 72 on the eve of the GOP convention. But their age difference, 25 years, is the largest in history for major party nominees. Obama must show he's mature and ready; McCain must show he's sharp and vigorous.

Both campaigns are rapidly adding staff. Obama's team will focus on introducing the first-term senator to voters who may not know much about his biography, while on Monday he begins a two-week economic tour of the country.

4. Raising money.

Obama has assembled an unprecedented political fundraising machine, raking in $264 million in 16 months. McCain has raised $115 million in 17 months. McCain, assured of his eventual nomination, had his best fundraising month in May, raising $21.5 million. Obama, reeling from controversies over his former pastor and still battling Clinton, raised nearly $32 million in April.

Obama should manage to continue this extraordinary accumulation of cash. McCain is improving as he works with the Republican National Committee to expand his donor base.

The Democrats' challenge is to build the party's finances. The RNC, now operating with McCain strategists in place, raised nearly $24 million in May and had $53.6 million on hand at the beginning of June. The Democratic National Committee raised nearly $5 million in May and ended the month with $4 million in the bank.

Obama is putting his stamp on the DNC, and has installed a top strategist to oversee general election operations. Separately, on Sunday, Obama named Matthew Nugen, his campaign's political director, to oversee operations for the Democratic National Convention in Denver in August.

McCain is preparing to accept about $85 million in public financing. But he needs approval from the Federal Election Commission, which cannot act until the Senate confirms nominees required for a quorum.

Obama is expected to turn down the hefty check and rely on private donors to finance his run.

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