Dispersant polymer for automatic dishwashing

An automatic dishwashing composition, comprising:

• a builder;
• a phosphonate;
• a nonionic surfactant;
• and
• a dispersant polymer, comprising:
• (a) 50 to 95 wt %, based on weight of the dispersant polymer, of structural units of a monoethylenically unsaturated monocarboxylic acid monomer;
• and
• (b) 5 to 50 wt %, based on weight of the dispersant polymer, of structural units of a sulfate bearing ethylenically unsaturated monomer;
• wherein the structural units of the sulfate bearing ethylenically unsaturated monomer are structural units of formula II
• wherein a is an average of 1 to 2;
• wherein b is an average of 2 to 20;
• wherein c is an average of 1 to 3;
• wherein each R2 is independently selected from a hydrogen and a —CH3 group;
• wherein each R3 and R4 is independently selected from a hydrogen and a C1-2 alkyl group;
• wherein X is a cation sufficient to balance the charge of formula II.