With the Democratic and Republican presidential nominees all but decided, attention turned Sunday to the possible contenders for vice president. Former House Speaker Newt Gingrich said he and his wife, Calista, “could be lured into a new path” if presumptive GOP nominee Donald Trump were to ask him to join the ticket. “If he can convince Calista and me that it’s doable and it’s serious and that we would in fact contribute, I think we’d be very hard pressed not to say yes,” Mr. Gingrich said on “Fox News Sunday.”