The statement 'On Optimism, by @mtaibbi' with a link to an article titled 'On Optimism - by Matt Taibbi - Racket News' and the description 'Feel better about everything, even belonging to the human race' does not provide enough substantive engagement with public issues, debates, or discussions. It appears to be a promotional activity for an article that may or may not address public discourse. Without further content from the article itself, it is not possible to determine if it substantively addresses public issues or policies.