The fall of the military junta in Argentina in 1983 began a spectacular Tango Renaissance in Buenos Aires. (...) And suddenly people wanted to learn to dance Tango, the ultimate symbol of Argentina to the rest of the world, because suddenly it felt all right to be proud to be Argentine again.
The problem with the Tango was that there had never been beginners' Tango classes in the Golden Age, and there was no tradition of teaching Tango. The prácticas had gone. There were no Tango teachers in Buenos Aires. There was a vacuum that needed to be filled.
Even in Buenos Aires, when the Tango Renaissance began, it was mostly young dancers who knew a little who were the first teachers. In 1983 many of the people who had been dancing in the Golden Age were not dancing, and those that were would still have been suspicious of strangers.
Gradually the people who had been dancing in the Golden Age, and who might not have danced for thirty years began to dance again. Some of them developed a passionate desire to pass on to the younger generation the dance that they loved.
from Christine Denniston (http://www.history-of-tango.com/tango-renaissance.html)