Ben Cutler (MacMurray) inherits a marshal's star after the lawman, his old friend, is killed while leading a posse in pursuit of bank robbers. Ben captures one of the gang, the youthful Eddie Campbell (Robert Vaughn), who killed the marshal. When Ben brings Eddie back into town some of the townsfolk want to lynch the bandit, but Ben stands up for the rule of law, determined to give Eddie a fair trial. Complicating his position is the crush Ben's daughter Laurie (Joan Blackman) has on the handsome outlaw, her childhood friend. In the audience's eyes, Ben has done the right thing, and since we saw objectively that Eddie had shot the marshal we expect no controversy, unless we recall that the movie still has something like an hour to go.
Somehow the town's ardor to hang Eddie cools over time, especially as the trial gets underway. A defense attorney, presumably hired by Eddie's at-large cohorts, casts doubt on the surviving posse members' ability to identify Eddie as the shooter in the confusion of the gun battle, but is unable to shake Ben Cutler from his (true) version of events. The lawyer's arrival introduces a discordant note of violence in Ben's stance. Claiming that Ben is eager to have Eddie hanged to keep the outlaw away from his daughter, the lawyer suffers a beatdown at Ben's hands before the trial even starts. Does Ben resent a lie or does the charge strike too close to home? The libel (?) hangs over him and spreads like a dark cloud as the jury convicts Eddie on Ben's testimony and the judge, despite Eddie's tearful plea for mercy, sentences the outlaw to hang. Now the worm has turned: having blocked the town's vindictiveness earlier, Ben now seems vindictive to almost everyone in town, including his new wife-to-be and his own daughter. The tension snaps when Ben discovers that Laurie had tried to smuggle a pistol (albeit empty) to Eddie in a meal she'd prepared for him. When she repeats the libel, he smacks her in the face.
The fact that the whole town turns against Ben suggests that Good Day For a Hanging has something more than the generation gap on its mind. For what it's worth, I don't think the film actually takes a stand for or against the death penalty. If Ben resents late attempts to spare Eddie's life, it's really only because he takes them personally as a reproach to himself. He never states explicitly that Eddie deserves death, and instead dutifully delivers a petition for clemency to the governor, who approves it. By that time, however, Eddie's cohorts have sprung him from prison, setting up a clarifying climax in which Eddie slaps Laurie down, disrespecting her devotion, before finally dying on the scaffold, though of lead rather than rope. Eddie's escape vindicates Ben, who is asked by contrite townsfolk to rethink his resignation. There's no High Noon finish here; Ben reclaims his star after reclaiming his authority in the eyes of the people. That gesture may make Good Day one of that small sub-genre of westerns that answer High Noon in one way or another. What it says on its own terms is interesting enough, however. It may not be too much of a stretch to see a Cold War metaphor at work, with Ben, like the U.S. as a whole, seeing himself as an embodiment of enlightened if not liberal values when he discourages lynching, yet seeing himself in the eyes of intimate critics as an oppressor if not a bully when he enforces order with force. Ben may embody that willingness to wage war, or simply kill, in defense of civilization that seems to belie civilization in the eyes of both idealists and cynics. Good Day makes more sense as a defense of that necessary resort to force than as a narrow defense of capital punishment, and if it strikes viewers as right-wing by taking the "authoritarian" or "patriarchal" side it's still worthwhile for evoking and addressing the anxieties of those who find their commitments increasingly thankless. As a plain old western it's a solid B movie from a studio that specialized in solid B westerns, as Quentin Tarantino acknowledged by claiming the vintage Columbia logo for Django Unchained. Juran is effective without being flashy and MacMurray is a good fit for the role, especially in retrospect after a generation playing the patriarch on TV. Vaughn is less successful in an early prominent role, mainly because the film stacks the deck against his character, denying the audience the townsfolks' prerogative to second-guess their attitude toward the outlaw. We never doubt that Eddie is a creep to the core, but if that costs the film some ambiguity we should remember that this is MacMurray's film, intended for audiences who'll identify with him. Good Day For a Hanging depends on your empathy with the star and main character, and MacMurray is good enough to earn that empathy and make this movie a modest success.