The most confusing part for me is why a declared 'National Socialist' would run as a Republican? Especially since 'National Socialism' is the motto of the Democrat Party.
This tells me that the guy is an unserious opportunist. He didn't run as a Democrat because he knew that he would never get the nomination, even though he is much more of a Democrat than a Republican. I'm sure he would run under any Party label whatsoever if he thought it would get him on the ballot. He is in it for himself, for name recognition only.
The fact that he is running as a Republican, does not mean that he is a Republican, e.g., John McCain. His choice of political Party is only coincidental because the seat was open and unopposed. Anyone could have jumped in. He just got there first. If the Democrat seat was open, he would be a Democrat.