This article is inflammatory distortion. There have always been wackos in any religion, but in the Church they usually end up getting excommunicated or silenced (ala Fr. Coughlin, Fr. Feeney, etc.).
"Traditionalists" is a pretty broad category, and the author is making some real leaps in assigning guilt by association. Furthermore, some of the groups he is talking about are not even part of the Catholic Church, having gone their own way long ago.
His purpose is clearly to defame orthodox ("traditionalist") Catholics in general and also to imply that the pro-life movement is a hotbed of anti-Semitism and racism. Nothing could be further from the truth, but truth matters little to leftists like the Southern Poverty Law Center.
I have a question, which I do not ask rhetorically, since I really don't know the answer. Does the "mainstream" of the traditionalist movement openly and clearly condemn antisemitism? For example, have the bishops of the SSPX issued statements or pastoral letters plainly condemning antisemitism? And have they taken steps to purge whatever antisemites may be in leadership positions? have they attacked the "Jews and freemasons" talk that is popular at tha radical fringe?
We often make the point that Muslims, if they are sincere about Islam being a "religion of peace", should be louder in denouncing jihadism and Islamofascism. By the same token, the traditionalists should take the lead in denouncing antisemitism.