Complex sentence: Krauskopf visited Jewish settlements in Palestine, and supported the Zionist movement for European Jews, while at the same time vigorously denied that American Jews had "dual loyalties," and was aggressively patriotic about his adopted homeland.
Split into simpler sentences: Krauskopf visited Jewish settlements in Palestine, and supported the Zionist movement the settlement of European Jews in Palestine. At the same time hevigorously denied that American Jews had "dual loyalties," and was aggressively patriotic about his adopted homeland.