Donald Trump’s speech Thursday night at the Republican National Convention was notable for its tone. As my Post colleagues Philip Rucker and David Fahrentold put it, “Donald Trump painted a dire portrait of a lawless, terrorized nation.” How dire? Consider this: Trump’s speech was the most negative in tone of any convention acceptance speech since 1972.

That is the conclusion of a new analysis by McGill University PhD student Denver McNeney. He measured the tone of each speech by analyzing its content using Lexicoder. This software compares a text to a dictionary of about 4,500 words and phrases that have been categorized as either positive or negative. This provides a sense of whether the text contains more positive or more negative words.

For example, McNeney gave me this example from Trump’s speech: “Any government that fails to do so is a government unworthy to lead.” The software would consider both unworthy and fails to be negative.