People forget that leaving was not an option for many. The antisemites in the State Department consistantly made sure taht despite demand, the number of refugees from Europe were always well below the hard quotas.
I'm well aware of that. At least some of those State Dept. bureaucrats were appointees of the great hero of all too many Jews, Franklin D. Roosevelt.
This subject is covered at length in the book "While Six Million Died," by Arthur D. Morse, published back in the 1960s.