(CNN) – The bookseller set to host a Newt Gingrich book signing Friday canceled the event, citing public safety concerns.The Republican presidential candidate and former House speaker was scheduled to visit Hudson News at Union Station in Washington, D.C. with his wife, Callista to promote her new children's book and his two most recent books. But Hudson News, located blocks from Capitol Hill, said it would not proceed, "in order to address public safety concerns."– CNN Political Producer Shawna Shepherd contributed to this report.