The vote is neither a right nor a reward nor a privilege.
It is an office.
This is Heinlein's point.
One who wields force on behalf of the state is an "officer".
He is not someone who has been rewarded with the power to wield violence. Nor is he someone who wields violence as a right or privilege, because he has no right whatsoever to do so beyond the exact scope of his duties.
Wielding this violence is his job. His office. And he is appointed to that office by reason of being qualified and verified according to a set of criteria.
And if wielding discretionary violence on behalf of the state is an office, so is deciding the policies and guidelines which define the scope of that officer's duties.
Thus, representative is also an office.
And if representatives are elected by vote, and are ultimately to be accountable to voters, then to be a voter, to be a member of the "demos" from which the word democracy derives... that, too, is an office.
There can be no question that the cutesy phrases modern leftists use to describe the vote, such as "exercise your rights", and "make your voice heard" are illegitimate and unjust.
To vote is to exercise control over the actions of others, and no one has a right to a "voice" in what others do.
The only legitimate reason for that control is to restrain others from anti-social action, which is a practical necessity, not an individual right.
Thus, the vote is an office, which must be held by those who are qualified — proven capable and willing to set aside their own interests and exercise power solely on behalf of the group.
This is Heinlein's point, elegantly and irrefutably argued.
This is why Heinlein is the greatest philosopher of the 20th century, and it is also why leftists hate him.
Because what is leftism?
It is a rebellion against civilization itself, motivated by the desire to tear open and loot the storehouse, to gut the accumulation of stored effort, wisdom, and self-control, the inheritance of all future generations, in an orgy of hedonistic consumption.
Leftism is the rats convincing the farmers that cats are fascists.
But just as cats were necessary for creating civilization, the officers of the demos, the citizens who can put aside their own desires and act in the interest of the republic, are necessary for preserving it.
The majority of the human race cannot or will not see beyond their own desires for more wealth, more pleasure, more status, and less work. They must be restrained even by the most libertarian of civilizations, because without that restraint, there is no civilization, and without civilization, no liberty.
America would be better off with only 10,000 voters, vetted for intelligence, prosocial attitudes, loyalty or America, and skin in the game. Perhaps even 1,000 would suffice.
Failing that, pretty much any test of competence, loyalty, or worth applied as a filter on the vote would improve America immensely. Net worth, ability to pass an algebra or reading comprehension test, anything.
The Constitution has no language forbidding any prerequisite for voting, other than sex, race, or the payment of a poll tax.
But first we must tear down the delusion that the vote belongs to everyone. Heinlein got us started.
Verhoeven himself put down the book due to the speech by Dubois (Raszack in the movie) in Johnny's class and much like the guy in the QRT, missed the point of it. The speech is not about how violence is a good thing. It's about the civilian franchise, the right to vote, is a form of force in it's own right and THAT is why it can't be a right, but a privilege.
Coincidentally it's also why he grills that one kid for saying voting privileges are a "reward." You don't reward someone a blank check to commit force upon others.