Place the popcorn kernels in a large, heavy-bottomed pot and cover with a tight-fitting lid. Heat over medium-high heat, listening for the kernels to start popping vigorously. Shake the pot gently every few seconds to ensure even popping, until the popping slows down significantly, indicating most kernels are popped.
Meanwhile, melt the unsalted butter in a small saucepan over low heat until fully liquid. In a separate bowl, whisk together the powdered sugar and orange juice until smooth and slightly thickened.
Once the popcorn is ready, remove the pot from heat and transfer the popcorn to a large mixing bowl. Drizzle the melted butter evenly over the popcorn, tossing gently with a spatula or wooden spoon to coat all pieces thoroughly.
Pour the prepared tangy glaze over the coated popcorn. Toss gently to distribute the glaze evenly, ensuring all popcorn pieces are lightly coated and glossy. The popcorn should appear shiny and slightly sticky but not wet.
Sprinkle the vibrant colored sprinkles or edible glitter over the popcorn while it's still slightly sticky, then toss again to evenly distribute the decorations. Allow the popcorn to sit for 5 minutes for the glaze to set and the decorations to adhere.
Serve the patriotic popcorn mix in a large bowl or paper cones, displaying the colorful, glossy, and festive snack ready for celebration.
