Anyone who has examined Richard Spencer’s choices for article acceptance as an editor of Radix Journal, can see there is a strong element of animosity and distrust toward the Jewish community present. That Kevin MacDonald is featured so prominently, is one sign, but there are other relevant publishing choices.
So, I do not think there is any doubt that NPI and Spencer are part of an anti-Semitic movement, but just in case you wanted some further evidence, IREHR provides a collection of choice quotes for you: https://www.irehr.org/2017/01/05/richard-spencer-alt-right-white-nationalist-anti-semite/
I do not know that a charge of ‘anti-Semitism’ is charge which either Kevin MacDonald or Spencer any longer would try to dodge. Still it is true, there are questions of different foci and even some Jews on the Internet, seem to hold for an idea that the ‘alt right’ movement will welcome them. I do not know what they mean by the ‘alt right’ – they could mean anything. But the term is tied in some ways, to ‘anti-Semitism,’ via the link between MacDonald and Spencer, etc.
The matter goes well beyond criticism of Israel or highlighting of the negative role some Jews have had in certain fields, e.g. Republican politics. MacDonald’s theories are quite a bit more extensive than noting, Jews too can be trouble-makers…. There is a notion offered of a neo-Darwinian account of the rationality of anti-Semitism.
As noted in the link above, the CSU has denounced MacDonald: although it was not clear in their statement, whether his main error was seen as lying with making general characterisations about groups or simply with the idea, having an ethnic characteristic might indicate an increased probability of a given political or social view. And one might interpret the first move in terms of the second, thus further confusing the issue. What was clearer was the note – which I hope is accurate – that MacDonalds’s writings include a ‘description of his own work as “rational anti-Semitism.”’