The main idea of the passage is To combat anti-Jewish propaganda, Irene Harand developed stamps showcasing Jews who had made important contributions to society. How does the detail in bold develop the main idea?

In the years leading up to World War II, the Nazi Party in Germany advanced extremely negative portrayals of Jewish people and culture. By depicting Jews as subhuman criminals, the Nazis sought to fuel public hatred. An Austrian woman named Irene Harand was concerned about the falsehoods being spread across Western Europe. To counteract the Nazi propaganda, Harand created a series of educational stamps, with each stamp featuring a Jewish person who had benefited society. For example, one stamp showed a picture of Benjamin Disraeli, a former prime minister of the United Kingdom, while another featured Paul Ehrlich, a notable scientist. Harand and her volunteers pasted their stamps on letters, next to regular postage stamps; they also secretly pasted them on the walls of an anti-Jewish exhibit. They hoped that the positive portrayals on their stamps would help counter the Nazis' malicious campaign to fuel hatred toward Jews.