1cupfreshly squeezed orange, blood orange, or cara cara orange juice (3 to 4 oranges)
1 ½cupsclub soda
thin slices of orange, for serving
Combine the orange juice, Campari, gin, and vermouth in a large glass measuring cup or pitcher and mix well. Stir in the club soda. Fill four glasses with ice and divide the drink mixture among them. Garnish with a slice of orange and serve.