👉 Insularism, also known as territorialism or isolationism, is a political ideology that advocates for the separation of powers between federal and state governments. It is often associated with the United States, where it was popularized by Thomas Jefferson in his book "The Federalist" (1803). Insularists believed that states should have more autonomy over their own affairs than federal government can provide due to the inherent differences between them. Ininsularism, while not directly related to the
