唯一两例总统弹劾的先例（包括1868年弹劾安德鲁·约翰逊滥用权力，以及1998年弹劾比尔·克林顿作伪证和妨碍司法）其结果均不尽如人意：这两者最终都被参议院无罪开释。
The only two presidential precedents (Andrew Johnson, impeached in 1868 for abuse of power, and Bill Clinton, impeached in 1998 for perjury and obstruction of justice) are hardly encouraging: both ended in acquittal by the Senate.