Hoover did not handle the Bonus Army well.
The Bonus Army was a group of 43 thousand protestors - WWI veterans and their families - who gathered in Washington DC to demand payment for their service certificates.
President Hoover did not attempt to negotiate with the protestors, first, he ordered to have them removed from government’s property and later he ordered to the Army to clear the marcher’s campsite.
To do so, infantry and cavalry was used and additionally, six tanks.
Public opinion on Hoover’s actions was strong, newspapers and newsreels - that were popular at the time - showed images of the violence perpetrated on soldiers and their families. This was considered one of the strongest factors that influenced his lost at elections to Roosevelt.