A presidential campaign is many things. It’s a race. It’s a fight. It’s a long-term venture and a high-risk investment. But for a presidential candidate — and for the voters, volunteers, and donors whose support he or she seeks — a campaign is also a conversation. It’s an effort to talk about issues in a way that engages people. It’s a bid to develop a rapport with current and would-be supporters. It’s a process that hinges on a two-way exchange of information: Voters tell the candidate what they care about, and the candidate tells voters what he or she stands for.