Sleazy and Wounded

This exchange has two primary authors: The Joes.

McCarthy and Welch had two vastly different tones because they were two vastly different guys.

McCarthy's tone was what the country had come to expect. He was confrontational and contemptuous, relying on sleazy innuendo to assassinate the character of whomever he was speaking to. When he saw Welch getting the better of Cohn, he leaned back on his most potent weapon—accusations of Communism.

Welch was extremely human here, going from something of a clown to embodying the wounded dignity of the American public. By standing up for someone else, Welch himself could remain mostly clean of insinuation, but still be as wounded by the accusation as though he were the target. He sorta was, since McCarthy was trying his whole guilt-by-association strategy. Welch, by adopting the role of noble, baffled defender, crushed him.