As part of his pre-K plan campaign, Mayor de Blasio visited a classroom at P.S. 130, on Baxter St. in the Chinatown / Little Italy area, Tuesday. He went with a classic — reading Dr. Seuss’s “The Foot Book” to the pre-kindergarteners, before giving it his mayoral endorsement. And before he left, if they wanted, he gave kids the option of a hug or a handshake with him.