Democratic strategist Joe Trippi thinks it will be virtually impossible for Sen. Barack Obama (D-Ill.) to win the home state of his rival, Sen. John McCain of Arizona, but that it's worth his while to compete.

Speaking on the last day of the Democratic National Convention in Denver, Trippi gave PolitickerAZ.com an assessment Obama's chances in Arizona, stopping short of completely ruling out an upset there but saying it would be "really, really tough."

"There's almost no way he can make it," said Trippi, "but he should definitely make an effort."

Trippi said a legitimate Obama operation in Arizona would send a message of strength, and could set up the Democrats to take the Grand Canyon State in 2012.

"The best he can hope to do is hold McCain to three points," he said, "but if he can do that, it puts them in a good position to win Arizona next time."

Trippi cited changing demographics, such as the loss of Republican Party dominance in voter affiliation and a population skewing younger, as welcome signs for Democrats hoping to pick up Arizona in 2012. He also had advice for how the Obama campaign should proceed.

"Obama's best bet is to focus on white women," said Trippi. His remarks came only hours before Alaska Gov. Sarah Palin was announced as Sen. McCain's running mate, which could make it tougher for Obama t target that sector of the electorate.