It's really interesting to compare the books Skeletor posted (issue dates and number/quality of reviews) versus the one from original post. Wonder how to explain it.
Some of the "reasons to vote Republican" books were released on March 9th and 10th and the "reasons to vote Democrats" book was released on February 8th. Most likely it is a concerted online effort to push a certain book/product to the front page in order to make a political statement. It seems to occur quite frequently in recent years with mass negative (or positive) reviews on amazon, yelp, google, comment sections of websites, mass reporting of content that "triggers" some people and of course the virtue signalling and slacktivism on social media.