Pedantic quibble. You're conflating representation with enfranchisementRepresentatives represent all those who reside in their districts whether they voted for them or not or even if they could vote.
Oh, so representatives in 1812 would've been just as democratic as today though no women or blacks were allowed to vote?
Or uh, just how are those who are not allowed to vote, able to ensure their representatives are in their government?

Women and ni
ggers in 1812 should've what---written letters to candidates pleading for them to acknowledge them? And that would've been just as good as if they had a 1:1 power votewise as to white males?
Silly "enfranchisment"! Has nothing to do with representation!
This would include minors, permanent residents, those on work visas, etc. Constituent services would respond to requests for assistance from minors and any teenager who cared enough to send their representative a message (call, e-mail, letter) is sure as heck going to vote when they turn 18. If their Rep. wants to get reelected, it's best not to alienate any of your constitutency.
Okay. Not sure what this has to do with a voting priviledge.
- eta, I'd also add that non-wage earners, like those on disability or stay at home parents pay no federal taxes, but still get the benefits of representation.
Your points about enfranchisement were spot on, but the last bit simply doesn't reflect reality.
I don't know what reality is then. I thought in context it meant voting rights, due to either existing as a citizen or failing that, earning money/thus paying taxes to a government.
Taxation without representation doesn't mean non-taxpayers-don't get representation btw, if that what's you're trying to mean with that disability persons thing. I don't know what you're saying actually.
Taxation without representation as a phrase means exactly as much to a 12 year old earning enough to pay taxes as it does a 31 year old not earning enough to do so or a 24 year old disabled not doing so. The general idea seemed to me to be: if your work contributes to the government's coffers, you should have the right to vote for the people that decide how those coffers are spent.
To finalize:
I think all citizens of a particular country should be able to vote for that country's leaders, as a requiring aspect of democracy. You apparently think differently.
ETA: My reasoning here ala taxation w/out represention is ridiculolus via those disabled unfortunates. Tax-w/out-rep is only my second most obvouis mandate of a democracy in general (first is just being a citizen), and only primary with regards to pre-18-year-olds getting screwed out of that phrase as an obvious inconsistency.