Answer:
if they conducted "treason, bribery, or other high crimes or misdemeanors"
Explanation:
This specific rule was written under the under Article II of the United States Constitution.
One of example of a big successful impeachment case was President Richard Nixon's impeachment in in 1974. At that time , he was caught after he ordered his people to break in to the DMC's office to steal some documents that might proof his illegal activities.
