Governments are instituted among Men, deriving their just powers from the consent of the governed ...Governments exist, period. The truism in the Declaration of Independence, relating to consent of the governed, pertains to "just" powers, not all powers.
I submit that the notions of "just powers" and "consent of the governed" have become bastardized , like much of the constitution. The government and courts (but I repeat myself) point to the vote, and equate it to consent. The logic goes something like this -- If everybody has the right to vote, then the government is one operated by consent of the governed. By implication, as long as consent is there, the people find the government action to be legitimate, or just.
The people aren't quite as dense as their government pretends: 19% Think Federal Government Has Consent of the Governed - April 2014.
I personally think the federal government operates so far outside of its constitutional boundaries, that it is reasonable to view it as mostly illegitimate.
Thanks for posting! Perhaps some on this forum could learn from it.