Low-temperature curing coating compositions

A coating composition comprising:

• an active hydrogen-containing, cationic salt group-containing film forming polymer;
• a curing catalyst in an amount of 0.01 percent by weight to 7 percent by weight based on total weight of resin solids and comprising a bicyclic guanidine and/or a bismuth;
• and
• a blocked polyisocyanate curing agent in an amount of 10 percent by weight to 60 percent by weight based on total weight of resin solids and comprising a blocking group derived from a blocking agent comprising an alpha-hydroxy amide, ester, and/or thioester;
• and
• wherein the composition is substantially free of tin, lead, iron, zinc, or manganese.