In a pitcher, combine pomegranate juice, vodka, orange-flavored liqueur, and fresh lime juice. Cover and chill until very cold, at least 1 hour (see notes). Just before serving, stir in ginger ale. Pour into ice-filled glasses. If desired, garnish glasses with thin orange slices.
You can make the juice mixture up to 1 day ahead; chill airtight (you can freeze the vodka mixture at least 1 hour and up to 1 day).