What's the Point of a Campaign Launch?

There's an innovation gap, i think, in the campaigns. Our non stop travel campaigns were important in the olden days. But now the news doesn't stop and everything's instant all the time. And really, it wouldn't be an election campaign without the campaign trail. So that's something to keep in mind as well. Ellen has a question about the campaign launches. She wants to know why they have an official launch after weeks of campaigning have already been done. What is the campaign launch and is there a point to it?