FACTBOX: McCain, Obama face hurricane risks, opportunities

(Reuters) - Rival presidential candidates John McCain and Barack Obama face an unpredictable series of political challenges from Hurricane Gustav's assault on the Gulf Coast.

Three years after Hurricane Katrina, the failed response of President George W. Bush is still a stain on his legacy and a hurdle for his Republican Party to overcome.

No politician wants to suffer the same fate. Some of the challenges for Republican McCain and Democrat Obama:

- Both candidates must find a way to show compassion for the storm victims and respond forcefully without looking like political opportunists. McCain visited a command center in Mississippi on Sunday and a relief center in Ohio on Monday; Obama said he did not want to strain emergency services by visiting the region.

- With a strong response to the hurricane at the party's convention, McCain could begin to bury the memories of Katrina and put a new face on the Republican Party. The party curtailed the agenda on the first day of the session and shifted to focusing on relief efforts.

- The storm, coming just days after the third anniversary of Katrina, could put the focus back on Bush. McCain has struggled to distance himself from the president, and does not need more attention on Bush during his nominating convention.

- Obama plans to galvanize his list of 2 million supporters to pitch in on relief work. But failing to visit the region could remind some of Bush's failure to visit New Orleans quickly after Katrina, and make Obama look uncaring.

- All of the governors in the affected states -- Louisiana, Mississippi, Alabama and Texas -- are Republicans, giving McCain an advantage in visiting and gathering information.

(Editing by Patricia Zengerle)