For the very reason that us as Americans have been in this two-party system for so long that we would want to keep this tradition rather than to add another party, and oppose eachother even more. Also, voters feel that having a third party vote is irrelevant because it is less likely to be voted for and won over.
Some flu victims had no H. influenzae in their lungs.
Civil Rights Movement was caused by the rampant discrimination of the segregation laws that had continued in the USA.
Explanation:
Segreagation laws were an arachaic practice that had continued in the USA even as the world was rapidly decolonizing and becoming increasingly free among its people.
Many countries had already achieved universal suffrage but USA was far behind in this thing from the other countrysides of the world
Thus the leaders felt that there was a need for revolution to bring constitutional equality to USA that it has always talked about in its constitution but never actually practiced in real.
