NAUDERO, Pakistan — Nawaz Sharif ventured into the political stronghold of his assassinated rival on Saturday and sought to make common cause against Pakistan’s president, laying a wreath on the grave of Benazir Bhutto and echoing her pleas for democracy.

Mr. Sharif, a former prime minister who had brought a raft of corruption charges against Ms. Bhutto and her family, needs to forge an alliance with her currently leaderless political party to challenge the government of President Pervez Musharraf. On Saturday, he flew on a chartered plane to Moenjodaro, where South Asian civilization was born some 5,000 years ago, and from there he drove in a long, dusty convoy of cars to this ancestral village of Ms. Bhutto’s, where senior leaders of both their parties met briefly to condole and discuss the way forward.