Robert Heinlein, in his collection EXPANDED UNIVERSE, tosses out several provocative ideas on different ways to choose elected officials. His own novel STARSHIP TROOPERS, of course, limits the franchise to veterans of Federal Service (NOT actively serving members; they can't vote until after discharge). (No, the political culture of the Federation in that novel is NOT the neo-fascist military dictatorship implied in that infuriating travesty of a movie adaptation.) Here's an essay analyzing STARSHIP TROOPERS in some detail:
Heinlein also brings up Mark Twain's "The Curious Republic of Gondour," a utopian society in which every citizen has at least one vote, but education or wealth can earn the individual the right to additional votes. The relevant portion of the story can be found here:
Another system proposed by Heinlein (how seriously, I can't tell) is a return to the requirement of property ownership as a qualification for the franchise, on the grounds that owning property proves the individual has a serious stake in his community. That idea gives me the chills, implying a reversion to the bad old days of the poll tax and other exclusionary tactics. At the very least, property couldn't be the only qualification. A college degree or employment in a skilled trade should be accepted as an alternative.
Most entertaining is Heinlein's comment about women's suffrage. When the vote was extended to women, many people assumed political discourse would rise to a higher, more morally pure level because of women's refining influence. Clearly, that result hasn't come to pass. Heinlein suggests we haven't gone far enough. How about disenfranchising males for a century or so and see what happens? It's only fair, right? :)