Both are in their early 30s, but are distinct characters – Mr. Sharif modest and earnest in a garishly orange jacket, Mr. Elahi full of purpose and youthful panache in a suit coat and designer loafers.
But together they embody the future of Pakistani politics, both its promise and its problems.
In separate interviews, the two men come across as open, frank, and idealistic – a blend of their Pakistani roots and Western ideals gained from studying abroad. The question for them, as well as Pakistan, is whether they and the new generation they will lead are earnest in their desire to recast the nation's politics of corruption and divisiveness or whether they will merely be consumed by it.
"People say, 'This is the way things are done in Pakistan,' " says Elahi. "If I can't [change] that, there's no point in me staying in politics."
For Mr. Bhutto Zardari, this election has come too soon. Because of Bilawal's youth, his father, Asif Zardari, will run the Pakistan People's Party (PPP) for the foreseeable future. In Bhutto Zardari's public press conference, held in London on his way back to Oxford, he freely admitted that he was not yet ready for politics.
"Although I admit that my experience to date is limited, I intend to learn," he said. "Unless I can finish my education and develop enough maturity, I recognize that I will never be in a position to have sufficient wisdom to enter the political arena."
More than 10 years older than Bhutto Zardari, Sharif and Elahi have already gone through that transformation, though in different ways. How they arrived at this moment – becoming the candidates their bloodline always suggested they would be – has deeply influenced what they hope to accomplish in the future.