As much as I despise Clinton history stands......both were convicted in the house and the senate let em go to the best of my knowledge......
http://www.infoplease.com/spot/impeach.html
Two U.S. presidents have been impeached: Andrew Johnson, the seventeenth chief executive, and William J. Clinton, the forty-second.
Johnson, a Southern Democrat who became president after Lincoln's assassination, supported a mild policy of Reconstruction after the Civil War. The Radical Republicans in Congress were furious at his leniency toward ex-Confederates and obvious lack of concern for ex-slaves, demonstrated by his veto of civil rights bills and opposition to the Fourteenth Amendment. To protect Radical Republicans in Johnson's administration and diminish the strength of the president, Congress passed the Tenure of Office Act in 1867, which prohibited the president from dismissing office holders without the Senate's approval. A defiant Johnson tested the constitutionality of the Act by attempting to oust Secretary of War Edwin M. Stanton. His violation of the Act became the basis for impeachment in 1868. But the Senate was one vote short of the two-thirds majority needed to convict, and Johnson was acquitted May 26, 1868.
On December 19, following much debate over the constitutionality of the proceedings and whether or not Clinton could be punished by censure rather than impeachment, the House of Representatives held its historic vote. Clinton was impeached on two counts, grand jury perjury and obstruction of justice , with the votes split along party lines. The Senate Republicans, however, were unable to gather enough support to achieve the two-thirds majority required for his conviction. On Feb. 12, 1999, the Senate acquitted President Clinton on both counts. The perjury charge failed by a vote of 55–45, with 10 Republicans voting against impeachment along with all 45 Democrats. The obstruction of justice vote was 50–50, with 5 Republicans breaking ranks to vote against impeachment.
You could say that Clinton was the only ELECTED president to be impeached.
Andrew Johnson was not elected as president, but of course was Lincoln's vice president (and a Democrat at that! - it was some kind of fusion ticket), and only became president when Lincoln was killed.
Maybe a minor distinction, but it is made. Certainly 1868, coming off a civil war (or whatever one wishes to call the conflict) was an unusual time.
Some would argue that the Vitenam War era was an unusual time as well.
What was Clinton's excuse, one might ask.
:)