Article II of the Constitution of the Democratic Socialist of America (DSA) describes the purpose of the DSA and starts with
We are socialists because we reject an economic order based on private profit, alienated labor, gross inequalities of wealth and power, discrimination based on race, sex, sexual orientation, gender expression, disability status, age, religion, and national origin, and brutality and violence in defense of the status quo.
Noble ideas. Take note of the section on discrimination. To be a member of the DSA, Article III of the DSA Constitution indicates membership is open to anyone who believes in the principles supported by the DSA. Article III goes on to say that members are in good standing as long as the dues are paid but also indicates that members may be expelled from the organization.
Article V of the DSA Constitution discusses the National Conventions which are described as "the highest decision-making body of the organization". Article V indicates representation at the National Conventions "shall be based upon dues-paying membership of the organization as of four months prior to the Convention". In other words, only card carrying Socialists will be represented. Looking back at the list of people that will not be discriminated against you will notice that having different political ideas is not listed as being protected and you can be thrown out of the party if you have different political beliefs.
Compare this to items 4,5 and 6 of the platform of the National Socialist German Workers Party of 1920:
#4. Only Nationals (Volksgenossen) can be Citizens of the State. Only persons of German blood can be Nationals, regardless of religious affiliation. No Jew can therefore be a German National.
#5. Any person who is not a Citizen will be able to live in Germany only as a guest and must be subject to legislation for Aliens.
#6. Only a Citizen is entitled to decide the leadership and laws of the State. We therefore demand that only Citizens may hold public office, regardless of whether it is a national, state or local office.
So it's not unprecedented for socialist organizations not to represent the entire population of a country. To say the DSA is against discrimination may be true, as long as you believe the same things they do. By the way, the National German Workers Part was the party of Adolf Hitler and the Nazis.
Article VIII of the DSA Constitution discusses the National Political Committee (NPC) referring to it as "the highest decision-making body of the organization between meetings of the Convention". The NPC is made up of 16 members of which "no more than eight shall be men and at least five shall be racial or national minority members of DSA". It may just be me, but if I'm the ninth male elected but can't join the committee because of this quota, I'm going to feel discriminated against.
It's hard for me to understand how individuals living in a country that protects their rights to form an organization like the DSA can support the organization when a similar organization to support political change would not be supported under DSA leadership. In addition, the organization espouses the belief in non-discrimination but sets up quota systems limiting the involvement of men and Caucasians rather than looking for the most talented to lead them regardless of their race or sex.
My question is what happens to those of that don't support socialism in a Socialist America. The National Socialist German Workers Party had a solution to the problem of dissidents and published it in their platform, item #18:
#18. We demand ruthless battle against those who harm the common good by their activities. Persons committing base crimes against the People, usurers, profiteers, etc., are to be punished by death without regard to religion or race.