A Poster That Legitimised Xenophobia in Sweden

About a year ago, the Swedish Humanist Association ran a national campaign against God. At bus stops and train stations, people were confronted with posters of three flags with religious symbols. Only one of them is the real Swedish flag—the one with the cross. The other two are fake.
The Humanists’ intention was to make people aware of the falsehood of theism. But God was not the one affected by the campaign; instead, people associated with Islam and Judaism were. As predicted by more intelligent critics, xenophobic remarks were common amongst the people who saw the posters. I personally heard it on buses when travelling about in Malmö.
In retrospect, I think this campaign—with its portrayal of Jews and Muslim as somehow less Swedish than others—opened the gates to the flood of xenophobia that has now resulted in a Nazi party being able to win seats in the Swedish Parliament.
I’m writing this now because the Swedish Humanist Association is desperately trying to distance itself from its own political agenda. Being the toughest critics of Jewish and Muslim culture doesn’t fit well with their image now that Nazis echo it.
I feel for the misguided atheists and would like them to learn from past mistakes. I have some advice I would like them to think carefully about.
Firstly, don’t ever contrast symbols of the secular state with religious symbols. Yes, there is a Christian cross on the Swedish flag, but most people don’t see it as a religious symbol in that context. The Swedish flag is a symbol for all Swedes, regardless of religion.
Secondly, rewrite your agenda. Remove all parts that single out specific religious and ethnic minority groups. Focus on the core issue, which in your case ought to be secularism and a state with no religious affiliations.