The Last Supper

The film centers on five graduate school students in Iowa who live together in a rustic home: Jude (Cameron Diaz), Pete (Ron Eldard), Paulie (Annabeth Gish), Marc (Jonathan Penner), and Luke (Courtney B. Vance).
After Zack (Bill Paxton), a Desert Storm veteran, helps move Pete's car, the group invite him to have dinner with them. However, Zack turns out to be a racist who praises Adolf Hitler and denies the historicity of the Holocaust, leading to a tense political debate with the liberal students. The evening takes a turn for the worse, when the veteran snaps and threatens to rape Paulie, then threatens Marc with a knife. Zack breaks Pete's arm but is stabbed to death by Marc. The group decides to cover up the murder. Paulie regrets that the man is dead, even though she and Marc were threatened.
After a long discussion led by Luke, the students decide to follow up this event by inviting other right-wing extremists for dinner to murder them, reasoning this would "make the world a better place". The students lay down a procedure for each murder. The guest will be given every opportunity to change his/her mind and recant his/her beliefs. If the guests fail to change his/her ways by dessert, the group offers the guest poisoned white wine from a blue decanter and raises a toast. The bodies are buried in the group's vegetable garden.
Guests include a homophobic protestant reverend; a misogynistic, chauvinistic rape apologist; a Neo-Nazi; an anti-environmentalist; a racist, anti-Semitic Nation of Islam fundamentalist; a Pro-life extremist; a censorship advocate; a hobo assailant (the only dinner guest who momentarily considers recanting his beliefs); and opponents of gay rights, all of whom are murdered. After ten murders, misgivings begin to surface within the group as a couple of them grow indecisive regarding the justification of their actions. Infighting and guilt compel Jude, Pete, Marc, and Paulie, in an almost unanimous decision with only the dissent of Luke, to spare a teenage opponent of mandatory sex education.
A local sheriff (Nora Dunn), who investigates the whereabouts of a missing girl named Jenny Tyler (Elisabeth Moss) comes upon the group. By coincidence, the main suspect in the case is Zack, the first victim, who was also a convicted sex offender. The policewoman grows suspicious of the studentsâ behavior and interrogates Pete, Marc and Paulie at their home. Finding the sheriff prying around the back yard after one of the murders, Luke, who is becoming increasingly unhinged, kills the sheriff unbeknownst to the rest of the group.
During a school break, Luke and Pete meet famous conservative pundit Norman Arbuthnot (Ron Perlman) and invite him to dinner. (Throughout the movie, brief segments of radical statements made by Arbuthnot had been appearing on the TV that the group had been watching in their home.) During the dinner, Norman stymies the group with his moderate and persuasive arguments, all of which the usually argumentative group have difficulty debunking. He even admits that he says more radically conservative things mostly for attention.
The frustrated students all suspiciously excuse themselves to the kitchen to determine Norman's fate. Jude warns him not to drink the wine in the blue bottle by saying, "It was left out too long and has gone bad." After a brief discussion, only Luke still wishes to kill Norman, calling him Hitler. After a tense altercation, where he aims a gun at Jude, Luke is dissuaded and breaks down into tears. Meanwhile, Norman examines the group's home and pieces together their murderous activities. When the students return to the table, Arbuthnot presents the group with glasses of wine and offers them a toast but does not drink himself, with the excuse that he doesn't want to be too intoxicated to fly his private plane. He puffs on a huge cigar and says, "Don't worry, I didn't pour any of the bad wine."
A closing shot of a painting portrays all five students collapsed on the floor, with Norman standing next to the blue bottle and smoking his cigar. The film ends with audio of Norman speculating about his possible presidential bid to a cheering crowd, pledging to do the people's will and describing himself as the people's "humble, humble, servant", and in the closing voice-over, Norman explains his reluctance to accept his fans' urging to take on the responsibility of "the highest office in the land" by explaining: "I already have."[3]

Question: Who dissented the sparing the life of the teenage opponent?
Answer: Luke.