WHEN Really Big Coloring Books published a 32-page children’s book about the Tea Party in 2010, the book received a lot of unwanted attention. The Los Angeles Times called it “kiddie propaganda art;” its author and publisher, Wayne Bell, said he received death threats.

“There was even a group of guys in New York that wrote a manifesto of how they were going to come down here and put me in chloroform headlock and throw me in the back of an ice cream truck,” Mr. Bell said.

But publishing houses like Mr. Bell’s have discovered that selling political literature to children is also good business. The Tea Party coloring book sold well, generating more than $100,000, at $3.59 each, in the first 30 days, Mr. Bell said. That may explain why, despite the threats, the St. Louis company released a sequel a few weeks ago, “Tea Party II, Why America Loves You! The Social-Activist Coloring Book for Kids.”

Political coloring books aren’t new, nor are they limited to one side of the ideological spectrum, said Fran Walfish, a Los Angeles-based clinical psychotherapist who specializes in children and families. In the 1990s, she said, there were coloring books about changing families, addressing themes like gay parenting.