I do not have an original source for that blog post but here's some stuff with sources
Openly identifying as a nationalist, and attending nationalist rallies, Navalny was kicked out of Yabloko for his nationalist views.
He created a movement (called “The People”) that targeted immigration.
Navalny called for the separation of Chechnya from Russia.
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He has spoken at the annual Russian March alongside leaders of various neo-Nazi organisations in Russia, many of which have been subsequently outlawed, with leaders arrested. Footage shows attendees flying banners with Nazi insignia, chanting racist and Islamophobic slogans, proudly Nazi saluting to the cameras, and bearing tattoos of Adolf Hitler and other Nazi insignia. Navalny confessed that he has attended the march for at least 4 years running.
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In 2007, on a live broadcast Navalny compared Muslims in southern Russia to tooth decay and cockroaches, imploring viewers to shoot them while he held a gun.
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In 2013, after ethnic riots took place took place in Moscow, Navalny championed the rioters for confronting “hordes of legal and illegal immigrants” on his blog.
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Also he was groomed by the CIA as a potential leader of Russia in the Yale World Leaders Program (funded by the NED, a subsidiary of the CIA), which had connections to the 2014 Ukrainian coup.
Source for this one unfortunately not longer exists as far as I am aware (dead link) but I thought it was worth noting if you want to look into it yourself
I also want to make it clear I am not someone who defends Russia nor Putin. I just think this is the last person we should glorify