Richard Nixon. He resigned on August 8, 1974, and had he stayed, he would surely have been impeached.
President Nixon was never impeached. He resigned because there were enough votes to impeach him. Bill Clinton and Andrew Johnson were the only Presidents to be impeached and both were acquitted.
Richard Nixon was not impeached. Three articles of impeachment were drafted by Congress but the case never proceeded. Nixon resigned to make impeachment a moot point and Ford's pardon of Nixon made indictment impossible.
Richard Nixon
The House is the body of Congress that has the power to impeach a president.
An U.S. President can be impeached for the following reasons: treason, bribery, and other high crimes.
The House Judiciary Committee conducts the formal inquiry into whether the president should be impeached. Based on their findings that recommend to the full house to impeach or not to impeach and submit the Articles of Impeachment ot the full house. The full house debates each article of impeachment and votes on each as to whether or not to impeach the president. If a simple majority votes to impeach the president on any or all of the articles of impeachment, the president will be "impeached." However, it is the senate who tries the president. See related question for more information.
The impeachments for each person would be separate, but they can most certainly be impeached at or near the same time. But that depends on how the House of Representatives wished to proceed - they could decide that handling both impeachment procedures concurrently would be too much all at once.
According to the Constitution, the President, Vice President, and all civil officers of the United States can be impeached and removed only for treason, bribery, or other high crimes and misdemeanors. Since the language is so broad, you could use many offenses to logically impeach elected officials. The term "impeach" does not in and of itself mean to remove someone from office. Impeach means to bring impeachment proceedings against them. For example, two presidents have been impeached: Andrew Johnson in 1868 for violating the Tenure of Office Act; and Bill Clinton in 1998 for lying to a Grand Jury (perjury). Both presidents were acquitted of the charges, and neither were removed from office. Contrary to popular belief, Richard Nixon was never impeached. He resigned the office of president before the House could impeach him. "The President, Vice President, and all civil officers of the United States" who may be impeached and removed only for "treason, bribery, or other high crimes and misdemeanors".[14] Several commentators have suggested that Congress alone may decide for itself what constitutes a "high crime or misdemeanor",
President Richard Nixon
Some Republicans did not think that a president could be impeached for not agreeing with congress.
The president is being impeached.
If the President were legally impeached and convicted, the vice-president would take his office and become President. No reason to think that he would be more dictatorial than Obama.