REASONS REQUIRED BY THE CONSTITUTION FOR IMPEACHMENT AND REMOVAL
http://www.archives.gov/exhibits/charters/constitution_transcript.html
Constitution Article II. Section 4.
The President, Vice President and all civil officers of the United States, shall be removed from office on impeachment for, and conviction of, treason, bribery, or other high crimes and misdemeanors.
DEFENSES AGAINST ILLEGAL ACTIONS
President Obama’s illegal actions cannot be stopped merely by electing a majority and not a two-thirds majority opposition in Congress. Previous illegal actions by the President cannot be rescinded, if President Obama vetoes all bills that attempt to rescind any of his previous actions. Also the President has issued executive orders to get what he wants when he could not get the Congress to agree to his proposals.
Impeachment is one possible defense against future illegal actions by the President, because he will run the risk of being removed by the Senate for such future actions. Impeachment of the President requires a majority of the votes of the members of the House, who are present and constitute a quorum when the vote is taken. Impeachment of a President constitutes an indictment of the President.
Removal or conviction of the President requires at least two-thirds of the votes of the members of the Senate, who are present and constitute a quorum when the vote is taken. The trial of the President, after indictment, occurs in the Senate with the Chief Justice of the Supreme Court presiding. If the Senate convicts a President, the President is removed from office.
The trial of the President can be valuable because it is required to be held in full view and hearing of the people. A public trial requires both accusers and defenders to present their arguments, in favor of and opposed to the President’s removal.
http://www.archives.gov/exhibits/charters/constitution_transcript.html
IMPEACHING THE PRESIDENT
Article I. Section 2, last paragraph:
The House of Representatives shall choose their speaker and other officers; and shall have the sole power of impeachment.
http://www.archives.gov/exhibits/charters/constitution_transcript.html
REMOVING THE PRESIDENT
Article I. Section 3, last two paragraphs:
The Senate shall have the sole power to try all impeachments. When sitting for that purpose, they shall be on oath or affirmation. When the President of the United States is tried, the Chief Justice shall preside: And no person shall be convicted without the concurrence of two thirds of the members present.
Judgment in cases of impeachment shall not extend further than to removal from office, and disqualification to hold and enjoy any office of honor, trust or profit under the United States: but the party convicted shall nevertheless be liable and subject to indictment, trial, judgment and punishment, according to law.