Near the end of Welch's smackdown, he utters the immortal line: "I like to think I am a gentleman, but your forgiveness will have to come from someone other than me" (Welch.90).

While this is not the most famous line from the exchange, it comes closest to Welch using McCarthy's tactics against him. Welch never outright states who McCarthy needs forgiveness from, but it's pretty obvious he means God. McCarthy himself was a Catholic, so it's likely this particular punch landed especially hard.

Welch's religious overtones get explicit when he caps everything off with, "If there is a God in heaven, it will do neither you nor your cause any good" (Welch.102). While that sounds weirdly atheistic to modern ears ("if there is a God"), at the time it was the perfect capstone.

One of the biggest differences drawn between the capitalist United States and the Communist Soviet Union was that the U.S. was a religious country as opposed to "godless" Communists. In 1954, the phrase "under God" was added to the Pledge of Allegiance, partly to distinguish the U.S from Communist countries, who were officially atheistic.

Welch is denying God's support of McCarthy's cause, which was taken as a given. In essence, any support God might have given vanishes in the face of McCarthy's immoral tactics.

It's not hellfire and brimstone, as Welch was not an especially religious man, but it is brutally sincere.