Yes, the United States should drop its sanctions on Cuba, because the sanctions haven't proven themselves to be very effective, it turns out. After fifty years of sanctions, Cuba is pretty much in the same place that it has been, and the people continue to suffer. We should take the approach that we took with the USSR, because that worked.
The Cold War is long over. The animosity that existed between U.S. leaders and Castro is all but dead (as is Castro himself). The United States has dealings with a number of countries who call themselves communist states and with dictatorships, as well. Cuba should be no exception. To keep to the old embargo now is nothing more than stubbornness and reticence to admit that Cuba managed to stay afloat without us.