You don't really need political clout directly, though it helps to get politicians in ones country to be invested in the project. Quite often it's politicians that directly start working on this, even.

The "protected designation of origin" is essentially a trademark that helps ensure that if you buy something marked "Parmigiano Reggiano" or "Parmesan", it's going to be cheese done using specific recipe, coming from its traditional, original region. It doesn't stop you from using the same recipe elsewhere, it just means you can't sell it as being the same. PDOs are generally used to protect local traditional products, though politics can get a bit cutthroat about it (I recall some... hot discussions regarding PDO for vodka)