Cuba is the only country that the U.S. government prevents its citizens from visiting. In fact, in the name of protecting freedom, the U.S. government can lock up citizens (and even some visitors) for simply going to this island.
It is a policy that clearly has not worked, and has given Castro a pretext for many of his abuses, such as the execution of three men who tried to hijack the Regla ferry in 2003, a couple of months after I had ridden it.
Every U.S. president since Eisenhower has supported the embargo, which makes no sense at all to most people who are younger than the Cold War. They did so to appease a small but vocal group in Florida who believed in the fantasy of reclaiming their long-lost wealth after a counter-revolution. Even most younger members of that community do not believe in the embargo any more.
I had the privilege (should have been a right) to visit Cuba in 2003 under an academic license that the Bush Administration took away in 2004. I would hate to live under its political restrictions, but as a U.S. citizen, I have the right to travel to a lot of places that have far more abusive governments.
From my perpsective the current president and vice president see this issue a bit differently from each other. I am very curious and a bit worried about how this will unfold, but I'm glad that some in Congress are pushing for change now.