Since they signed a contract to do so?
"It was shocking" said RAVEN Magazine publisher Zane Valenti, "because I thoroughly explained the magazine's tone and type of content to the Vice President months ago before accepting the print bid, and did so to avoid exactly this problem. I had warned her that the humor was very irreverent and often critical of the current White House administration. She assured me on each point that there would be no problem."
But since she obviously breached the terms of the contract, they DO have a legal standing, in refusing to print it.