And eligible voters do just that. Ineligible voters can’t vote.
District size is constant at about, what, 800,000 people per district? I forget… I think it’s the number of districts at issue, not district size in either population or geography.
EDIT: Let’s see: 320 million people divided by 435 Representatives = 735632.18 people per district. For argument’s sake, we’ll count the 0.18 of a person as a teabagger.
In my very limited understanding of the subject, that’s why one man - one vote was enshrined as a principle and an apportionment of numbers of districts was made in a manner so as to keep district size constant. Before that, places whose district boundaries were made based on criteria other than keeping population constant diluted the influence of each individual voter in more densely populated districts.
My own layman’s thinking is that since Congressional districts have a direct effect on how the Federal government interacts with its citizens, and since even those who can’t vote are subject to those policies, benefits, and taxes, theoretically at least our elected representatives are doing their job for everyone who lives in their district — whether or not a person happens to be registered to vote, is a convicted felon and deprived of that right, or whatever.
Just because you aren’t registered to vote doesn’t mean you aren’t represented. Don’t forget: everyone pays taxes, even the so-called “illegal alien” these people rail against.