Robert Mueller wast tasked as special counsel, with leading the team investigating Russia’s influence on the 2016 presidential election by Rod Rosenstein including any connections to Americans, and to investigate any crimes that come up while investigating.
Donald J Trump called it a “Witch Hunt” on hundreds of occasions.
If it was a witch hunt, then it was a successful witch hunt, that found witches, enough evidence to charge a normal citizen with obstruction of justice, but did not find enough admissible evidence of collision with Russia and the Trump campaign, due to the fact that multiple witnesses lies to investigations and Congress and destroyed evidence of their crimes.