Previous runners up are BAQ!
Some months, the second place winners only got 4 votes, so I picked books that had 8+ votes.
How Migration Really Works: A Factful Guide to the Most Divisive Issue in Politics by Hein de Haas, 436 pages
https://www.goodreads.com/book/show/82005192-how-migration-really-works
Bad Mexicans by Kelly Lytle Hernandez
https://www.goodreads.com/en/book/show/58999198
Investigative Aesthetics. Conflicts and Commons in the Politics of Truth by Matthew Fuller and Eyal Weizman, 272 pages
https://www.goodreads.com/book/show/57847186
The Misinformation Age: How False Beliefs Spread by Cailin O'Connor
and James Owen Weatherall, 280 pages
https://www.goodreads.com/book/show/39644428-the-misinformation-age