Make sure you read to the end of that article. Nevalny himself (NPR interview, maybe?) admitted that he has courted the far right as well as the left in his bid to expose corruption within the Russian system and gain enough support to attempt to topple the Putin regime. He is unapologetic about it as he feels his intent (to clean up Russia and push for democracy) justifies his acceptance of all Russians as fellow countrymen. Like most people seeking power, his path is not pure and his antagonists will use that to poison any positive message he presents.
It’s South Fucking Dakota, who the fuck else is there to vote and to vote for? And he’s a senior senator - he could just drop out and sit on his cushy retirement on his ranch (I’m assuming he has a ranch because, well, don’t they all?)