The final volume of the report by the Senate Intelligence Committee’s Russia investigation arrives late in the game. Still, it offers the detailed accounting of how Russian spies worked with the Trump team that former special counsel Robert S. Mueller III should have given the country last year. It offers raw material for the wide-ranging impeachment inquiry that the House of Representatives should have conducted.

Here at last is hard evidence — certified by GOP committee leaders and published this week — that shreds Trump’s false claims of a Russia “hoax” or “witch hunt.” Let us never hear that glib dismissal of fact again. From now on, the simple answer to Trump is: “That’s not what Senate Republicans found.”

The document is 952 pages, stuffed with obscure names and details, and few will read much of it. But as someone who has spent four years examining arcane aspects of this story, I can summarize the findings that make the report so powerful.