Only in Essex Steamer Clam Cakes with Traditional New England Tartar Sauce

Name: Only in Essex Steamer Clam Cakes with Traditional New England Tartar Sauce
Ingredients: 1 large Vidalia onion; 1 can beer (Budweiser or the like is fine); Olive oil; 6 pounds steamer clams; 1/4 cup onion, finely diced; 1/4 cup dill pickles, diced; 3/4 cup mayonnaise; 1 tablespoon pickle juice; 2 cups canola oil or more, according to manufacturer's instructions on deep-fryer; 3 cups all-purpose flour; 2 teaspoons baking powder; 2 teaspoons salt; 2 eggs, lightly beaten; 1/2 cup evaporated milk; 1 1/2 cups clam broth; Lemon wedges, if desired