Hi! Welcome to the site. If you haven't already, consider reading the Hubski Primer as it will explain the basics of the site. I also recommend going through the Badges page, or filtering your feed by 'posts with lots of upwheels' which you can do in the top right corner, below the header.
Where do you see the abundance of Marx posts? There are three #marx posts made in the last day, all by one user. I wouldn't call that a great amount. That said I do think that Hubski is leaning quite to the left when it comes to US politics.