The Pew Research Center tells us more of what we already know, namely that restoring ties (and even ending the embargo) with Cuba is very popular both in the United States and in Latin America.
Opponents of the changes say that popular opinion shouldn't drive policy. This is true, though in this case common sense coincided with public opinion. But public opinion will help explain why policy changes won't get changed back if a Republican is elected president. It costs very little to staunchly oppose change, but it is very costly to actively remove a policy that many people--even in your own party--like.