Colbert unloaded a full chest full of Irish spirit in his "Formidable Opponent" piece last night:
The episode's here, and it's in the second segment and features the well-practiced WOOOO that lets you know he had a childhood full of mosquitoes, high-fructose corn syrup, and burning his ass on infernally hot playground slides. (In other words; our brethren from the WOO Belt.)