"He does.  He maintained occupation of it, unassisted, for the required length of time.  Smith is the planet Mars - King, President, sole civic body, what you will.  If the skipper of the Champion had not left colonists behind, Smith's tenure might have failed.  But he did, and that continues occupation even though Smith came to Earth.  But Smith doesn't have to split with them; they are mere immigrants until he grants them Martian citizenship."