[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2009/POLITICS/08/10/political.families/art.bush.gi.jpg caption="George and Jeb Bush are the only sons of a president to make it to the governor's mansion."]
(CNN) - For some families, like the Kennedys, the Bushes and the Roosevelts, politics runs in the blood. But as history shows, coming from a powerful political family doesn't mean a free ride to the top.
"It does help, and it hurts. It's a two-edged sword," said Doug Wead, a presidential historian and former adviser to President George H.W. Bush. "It initially helps the candidate with name recognition and more importantly with fundraising ... but many vote against the child as well."
The children of political families inherit a treasure chest of contacts, campaign workers and often endorsements, but the benefits have their limits.
Only two presidential sons have followed their fathers to the White House (John Quincy Adams and George W. Bush), and just one presidential family - the Bushes - has sent sons to the governor's mansion (Jeb Bush in Florida and George Bush in Texas).
"I conclude that a brand name - a famous family name - is typically worth one step up on the political ladder," said Stephen Hess, a senior fellow emeritus in governance studies at the Brookings Institution, who has researched and written about political dynasties dating back to colonial times. "They get one step up - and they are on their own."