Movies You Haven't Seen But Should: Seven Days In May

Seven Days in May on the IMDB:

At the height of the cold war, a weakened President and a popular four-star general face off in a battle for control of the US government. President Jordan Lyman has successfully negotiated an arms reduction treaty with the Soviet Union, but his measure is unpopular and does not sit well with General James Mattoon Scott, the Chairman of the Joint Chiefs of Staff who has been quite vocal in his opposition. Marine Corps Col. Jiggs Casey, who works for Scott, comes to the conclusion that senior military officers are plotting a coup to overthrow the government. Working with a small circle of reliable and loyal officials, President Lyman tries to get the evidence of Scott's treachery and stop him.

General James Mattoon Scott: And if you want to talk about your oath of office, I'm here to tell you face to face, President Lyman, that you violated that oath when you stripped this country of its muscles - when you deliberately played upon the fear and fatigue of the people and told them they could remove that fear by the stroke of a pen. And then when this nation rejected you, lost faith in you, and began militantly to oppose you, you violated that oath by not resigning from office and turning the country over to someone who could represent the people of the United States.
President Jordan Lyman: And that would be General James Mattoon Scott, would it? I don't know whether to laugh at that kind of megalomania, or simply cry.
General James Mattoon Scott: James Mattoon Scott, as you put it, hasn't the slightest interest in his own glorification. But he does have an abiding interest in the survival of this country.
President Jordan Lyman: Then, by God, run for office. You have such a fervent, passionate, evangelical faith in this country - why in the name of God don't you have any faith in the system of government you're so hell-bent to protect?