Which logical fallacy does the example contain Congress smith opposes military action because he is weak and cowardly?

The example contains an ad hominem fallacy, which occurs when an argument attacks a person's character or attributes instead of addressing the actual issue or argument at hand. In this case, Congress Smith's opposition to military action is dismissed based on personal qualities (weakness and cowardice) rather than engaging with the merits of his stance on military action. This undermines rational discourse by shifting focus from the argument itself to the individual.