The “Godmother of Punk” sings about one’s connection to their country in 1979. The space between ‘Citizen’ and ‘Ship’ may be another way of referring to a country, as a naval vessel of people. That kind of a craft may have leaks if people don’t feel connected to its course.
Having citizenship, without the space between, is like having legal membership in a country. The membership card is often a passport or other official government document.