Blackberry Margaritas

1 (16.5 ounce) can blackberries, including syrup
1/4 cup tequila
2 tablespoons orange liqueur
1/4 cup lime juice
2 cups crushed ice

Blend berries and syrup in blender for 10 to 12 seconds. Add remaining ingredients and blend until ice is almost smooth. Pour into 12-ounce glasses.