The Chief Excecutive
Congress
impeachment
It is known as impeachment.
Bill Clinton
President Clinton was removed from office.
The Senate
No- the vote was 126 to 47 in favor of impeachment.
It is the House of Representatives that has the power to impeach a president. His or her trial is then held in the United States Senate.
The Supreme Court plays no role in impeachment trials. However, in the impeachment trial of the President of the United States, the Chief Justice of the United States serves as presiding officer of the Senate since it would be a conflict of interest to have the vice president presiding over a trial at which he would become President if the current President were to be found guilty.
Andrew Johnson Andrew Johnson
The President does not have to accept or "obey" impeachment. It is like an indictment and causes the Senate to hold a trial. The President does not have to respond to the trial. If he is found guilty by 2/3 of the Senators, he loses his office and is no longer President. If he is acquited by the Senate, that is the end of the matter and he stays on as President.
As President of the Senate, the U.S. Vice President presides over most impeachment trials. However, Article I, Section 3, Clause 6 of the U.S. Constitution specifies that when the President is on trial the Chief Justice of the Supreme Court presides. And although the Constitution doesn't say, I assume that would also be the case if the Vice President were the defendant in an impeachment trial (an incumbent U.S. Vice President has never been impeached to date).