Final answer:
To have the Democratic support for Hayes following the election, he needed to withdraw federal troops from Southern states.
Step-by-step explanation:
According to the Compromise of 1877, in order to have the Democratic support for Hayes following the election, he needed to withdraw federal troops from Southern states. This move effectively ended Reconstruction and allowed Southern Democrats to regain control over their home governments. The withdrawal of federal troops from the South was an important concession made by Hayes to secure the support of Southern Democrats.