Different states have different age requirements which I think falls under the 10A, but in the case of IL, do they have a right to confiscate? IMHO, that clearly denies the right to bear arms. Making the law that one has to be 21 I see as different but to confiscate guns that are already owned is quite another!
From my understanding though state law does not override federal law IF it violates the Constitution. Anyone? Please correct me if I'm wrong on this.
I think that's basically right, LB, with respect to a right protected by the Constitution. The individual RKBA was not recognized as Constitutionally protected until the Heller decision. And I would think that the ability to regulate the right would be analyzed similarly to how other judicially-recognized Constitutionally-protected rights are addressed.
Here's the crux of it - gun purchases are being denied to a class of adult citizens on the basis an arbitrary characteristic - their young age - on the basis of harm or potential harm caused by a very small percentage of the affected population. Yes, these are young people, and we all know that certain privileges of adulthood - booze, cigarettes - are denied them. But they are adults - they can marry, vote, enter into legally binding contracts.
And, of course, serve in the military. That's especially important, because the usual argument with age-based restrictions - that young people aren't physically or emotionally mature enough to handle the responsibility - cannot possibly succeed when the military draws much of its recruiting from the 18-20 age cohort.
Distinctions in the law based on arbitrary characteristics are most difficult to defend when we're dealing with so-called protected characteristics. Like race, ethnicity, gender, religion, sexual orientation in some places. There is heightened scrutiny, even strict scrutiny, applied to discrimination on the basis of a protected characteristic. The reason you can't pass a law to keep blacks, or Jews, or women from buying guns is that there is simply no defensible rationale for the restriction - and if there is, it can be accomplished less restrictively than a class-based ban. Yes, statistics may show that blacks commit proportionately more crimes with guns than other races (they're victimized more by guns too), but that does not support banning blacks from owning guns, since the law can accomplish its purpose less restrictively by only banning gun ownership by felons (of whatever race).
But is age a protected characteristic? Well, yes and know. For employment purposes, OLD age is a protected characteristic, but it is hardly clear that young age is similarly protected. And workers are protected with respect to old-age discrimination by specific laws to that effect - and age restrictions for the purchase of firearms are common at the state and local level.
If (young) age isn't a protected characteristic, then the courts ordinarily permit laws to draw arbitrary distinctions so long as the restriction has a rational relationship to the problem the government is trying to solve or goal the government is trying to achieve. And I think that's where the battleground will be - is government acting rationally to the problem of school shootings by denying entirely the right to purchase firearms to an entire class of people without regard to conduct?