IF the majority did not approve of the way our courts do business when it comes to constitutional law, including judicial review and/or scrutiny in relation to the 14th Amendment, then they are free to change that through Amendment. Until that point, then the people either don't care enough or agree with how it is done.
We don't treat everyone the same, and that is the point. In how you are trying to use the 14th, without states being able to justify treating 16 year olds different than 18 year olds, then they would have to be treated the same. Why aren't they? Why are states allowed to treat 17/15/16 year olds differently than 18 year olds? Please enlighten us all because it is obvious that they are allowed to do so.
Your claim is that it is the will of the majority that allows this, but that is not true. It is because the will of the majority in this mattered is justified by furthering a legitimate state interest in establishing an "age of majority". The will of the majority would be invalid if it tried for treating different ages differently, such as saying that a 36 year old could not get married but anyone 18-35 and 37 and older could.
Your wording is somewhat ambiguous, so I cannot really tell if you are recognizing that different states DO get to treat 16/17/18 year olds differently by state. For instance, in the area of legal sexual consent, the states are all over the place on the issue with many allowing it at 16, many at 17 with about 2/3s having it at age 18 and above...so what is the difference... and if you move from a state that allows for consent at 16 to as state that only allows 18+, would your mental abilities to judge circumstances just automatically diminish by simply crossing the state line?
Alcohol consumption is generally 21, but South Carolina allows the possession and consumption of alcohol by adults 18 to 20 years of age... so this is not uniform across the nation, nor should it be.
Local and state communities indeed should be able to determine what is allowable and what is not in their state and their communities... that has been one of the geniuses of our system of Federalism, power sharing/division between state and national government.
The Federal government has simply and obviously overstepped its proper boundaries, based on the promises upon which our framework for governing, our Constitution, was sold to the states. Further, upon which these states voluntarily gave up their independence, and only a portion of their sovereignty, based on this Constitutionally established system of power sharing/power division with the Federal government limited to only the enumerated and with minimal necessary additional powers to carry these out these specific powers, curbed with extremely reasonable limitations as to how far they could go [
as there was a lot of prescient doubt that the Federal government would stay within its agreed bounds ]... and so, as predicted, the Feds have gone too far.
The 14th, while necessary, well meaning and attempting to help a nation heal/adjust from a major war within itself, was surely never meant for what it is now being warped to intend. The 14th needs a whole lot of scrutiny, fine-tuning/correction as to meaning... certainly limits in place so it does not get to the outrageously absurd.
The current situation is a prime example.