Edit, since folks don’t seem to get the joke: Obama’s campaign slogan was “Hope”
“Dubya” is a nickname for George W. Bush that was coined by newspaper columnist Molly Ivins. The name is a Texafied pronunciation of the letter W.
Dubya was the President from 2001 to 2009, in the two terms preceding Obama. Rumsfeld was Dubya’s defense secretary, and Cheney was the vice president.