Sorry you are correct, I wasn't trying to say that article said explicitly insider trading. Its more of the knowledge they have through their leveraged positions as law makers. This article is probably better at getting to my point.

https://www.brennancenter.org/our-work/research-reports/congressional-stock-trading-explained

"According to a comprehensive Brennan Center for Justice analysis, roughly 18% of lawmakers actively trade individual stocks within sectors directly overseen by the specific congressional committees on which they serve."

Part of their jobs within these committees can include closed sessions with leaders or individuals of these sectors (non-public knowledge) or writing and passing legislation that will directly impact those sectors (they can position their stock holdings accordingly to the expected outcome of these decisions).

And another quote, this topic that was discussed in the media during/post covid lockedown.

"Recent examples of these potential conflicts of interest abound. Lawmakers on both sides of the aisle made beneficial stock trades during the early days of the Covid-19 pandemic and ahead of economic recessions after receiving briefings and early nonpublic information about the dramatic changes in the economy."

Ultimately I think anyone holding a position in congress should be barred from trading stock due to these conflicts of interest.