Here's a brief explanation of what we're looking at:
"But any change in U.S. policy is not in the works anytime soon, several observers say, because of President Bush's hardline stand on Cuba and the 1996 Helms-Burton Act, which set tough conditions for lifting the embargo.
The conditions include allowing legal political activity, the dissolution of Cuba's secret police and a public commitment to organize free and fair elections that do not include either Fidel or Raúl Castro."
And concerning the presidential candidates:
"Of the three major presidential hopefuls, Sen. Barack Obama has signaled he would eliminate restrictions on Cuban American travel and remittances to the island but would keep most of the embargo in place. Sens. Hillary Clinton and John McCain have said they do not plan to ease Cuba sanctions."
http://www.miamiherald.com/news/breaking_news/story/424248.html