And if Timothy McVeigh had done the same thing in some foreigh country, maybe on instructions from a president trying to divert attention from his domestic embarrassments, would people feel any differently about him?

Yes, and if cat turds were caviar we'd provide them with oer d'ouevre trays instead of litter boxes. I don't think the way to win an argument against capital punishment is to try to excuse the actions of Timothy McVeigh. What he did is detested by most people who know anything about it. What should have been done to him because of what he did is open to discussion.