Leadership is about setting a direction. It's about creating a vision, empowering and inspiring people to want to achieve the vision, and enabling them to do so with energy and speed through an effective strategy. In its most basic sense, leadership is about mobilizing a group of people to jump into a better future.
I know of not one Republican candidate that would not appear publicly with Mitt Romney and I know many Democrats that don't even want to be in the same city - forget the same stage - with President Obama.