What does “that goes double” mean in English?

When someone says “that goes double,” they are not talking about the number two. They mean: what I said before is true — and now it is even more true here. You can use it to agree with someone or to add weight to your own point. It is a short, natural phrase that works in conversation, interviews, and everyday talk.

In the clip, a political analyst has just said that Australia’s shifting vote share is exciting news for election analysts. He then adds: “that goes double now that we are in an electoral universe that is utterly unrecognizable from the one that we’ve lived in all our lives.” He means his excitement is even stronger now, because the political world has changed so much. You hear the phrase in everyday situations too. A parent might tell two children: “No running inside — and that goes double near the stairs.” A coach might say before a final: “We always warm up. That goes double today.” The phrase usually comes right after a statement the speaker wants to strengthen, often introduced with “and” or “but.”