I hate this lazy faux-patriotic pundit trope about National Unity. That isn't actually what the political process is about. In a liberal democracy it's about implementing the will of the majority, with plenty of protections for the minority (or -ties) limiting that power. Quirks of various systems limit the ability of the elected majority to assert power more even more. The only "unity" necessary is that we agree not to kill each other and instead fight it out in the next election. It's a way of resolving disagreements, not removing them. And the day after election day all of those disagreements and hatreds will still be there. It's somewhat important for elites to pay respect to certain ideals like "peaceful transition of power" and "the person&party that win get to govern" but that isn't about "unity."
It gets accompanied by people bleating about how we need to be able to get along, and talk to each other, and love the people we disagree with politically, and write big checks to the people who set up organizations claiming to be dedicated to these ideas. Yah, well, most of us live in this world and have friends and family and coworkers who we have to talk to and get along with etc. and it has nothing to do with "unity" just being a fucking human being who can usually manage to go to a dinner party without fighting with the host about some stupid shit Sean Hannity said yesterday.
And that's even without mentioning what "unity" really means, which is "shut up and eat the shit we feed you, peasant."