I would like to preface this article by saying that it is not as "serious" as many others you may find on this site. It is more of a thought experiment than anything else. I do not advise using it in any other sense, and it is certainly not intended as legal advice. As a matter of fact, I am not currently, nor have I ever been, a citizen of the U.S., and am in no way licensed to practice law.
What I am, however, is a free, critical thinker, a faithful, knowledgeable Christian, a "stronger brother", and, to a significantly lesser extent, and for lack of a more descriptive term, a political libertarian. What that means is I have put a lot of thought into issues such as religious liberty.
Again for lack of better term, the Bible is very libertarian. I say for lack of better term because I literally cannot think of a better term, however in the modern day, the word "libertarian" has come to mean Liberal lite. Thus, let me spend a moment to define what I mean when I say it (and if anyone smarter than me can think of a better term, I would appreciate hearing from you).
What I mean by the Bible is libertarian is that, while there are obviously moral rules (e.g. the 10 commandments), it also presents a mindset that anything which is not explicitly forbidden is implicitly allowed. Things which are not explicitly forbidden are called "doubtful things". Vegetarianism is the perfect example. The Bible does not explicitly forbid eating meat, yet not everyone feels they can morally justify eating meat. Carnivores are not allowed to judge vegetarians, vegetarians are not allowed to judge carnivores. A Christian can choose what they will and won't eat. This is best described in Romans 14.
Apart from Romans 14, we also find various other descriptions of the liberties Christians enjoy in our Lord. Colossians 2:16-17, for example, reads "Let no man therefore judge you in meat, or in drink, or in respect of an holyday, or of the new moon, or of the sabbath days: Which are a shadow of things to come; but the body is of Christ." This is very clear, even explicit permission for Christians, feeling no personal conviction, to drink whatever they see fit. We can also combine this with celebrations, which typically involve drinking.
Now consider the words of the first amendment of the United States Constitution: "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the government for a redress of grievances."
The First Amendment is often erroneously summed up as the freedom of speech, but in reality, it is the freedom of expression. Not only do American citizens have the absolute legal right to say what they like, but also to express any religious value they want, and that cannot be legally taken away from them. The only exception would be violent actions. Note the word "peaceably".
Now, suffice to say, Christianity is a peaceful religion. You cannot get more peaceful than "Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you;" (Matthew 5:44) or "If it be possible, as much as lieth in you, live peaceably with all men." (Romans 12:18). Christianity literally commands peace, and so there should never be any reason for any government, American or otherwise, to want to limit it. If anything, if they desire peace, they should want it to spread far and wide. But even if we ignore the fact that Christianity as a whole is peaceful, drinking is also a very peaceful thing. It can turn violent if the one drinking lacks self control (and the Bible does condemn drunkenness), but drinking in moderation is entirely permissible.
All of the above means that drinking is a religious issue. You could even make the argument that this extends beyond Christianity. I don't know about other religions, but the Constitution doesn't make any exceptions. The government cannot say, for example, that a Theistic Evolutionist, given that he has compromised his faith by polluting it with a secondary, contradictory religion, has forfeited his right to religious freedom. So, if you are a Muslim, your religion says you can't drink at all, but you can decide that you like the Christian libertarian view on alcohol. Or even if you're an atheist, you can absolutely say that, since you like the Christian libertarian view, you accept that part of Christianity. In all cases, therefore, drinking is a religious issue.
As I write this article, the legal drinking age in the U.S. is currently 21. But let me ask a few questions. What is the legal age to attend a Sunday service? What is the legal age to get baptised? What is the legal age to celebrate Christmas? What is the legal age to read the Bible? The answer is that none of these have a legal age limit. Nor can Congress legally or justifiably apply one. Imagine a world where they could. They would be able to circumvent the Constitution simply by raising the age at which they are applied. They could effectively ban religion simply by saying you have to be above an unrealistic age before you can convert to it.
To summarise the above, since drinking is a religious issue, the drinking age, especially such a ridiculously high one, is the prohibition of the free exercise of religion. The First Amendment legally prevents the government from prohibiting the free exercise of religion. Therefore, by judging under 21 year olds in their drinking habits, Congress has violated the First Amendment.
Now, would this case hold up in court? In truth, I do not know. I will say, however, that it absolutely should. The only alternatives are:
Violate, or as some might say "reinterpret, the specific wording of the First Amendment, suggesting that there are some peaceful religious expressions that the Federal government can legally prohibit.
Suggest that the Constitution is less authoritative than the Federal government.
Both of these have the same problem. The Constitution is designed to protect the rights of the U.S. population from government violations, as well as provide a framework for law and order, and define the roles of government. Option 2 is the denial of that, and option one is the nullification of that. If the Constitution means what it says, yet the federal government can nullify it, then the American public do not really have any legal protections for their rights. Laws can be legally made which violate them. One could argue very strongly that this already happens, but these violations are, by definition, unconstitutional, and therefore illegal. Option 1 would allow the Constitution to remain authoritative for all intents and purposes, but too ambiguous to be worth anything. It may as well be the Mona Lisa, it's that meaningless. Either the First Amendment protects all peaceful religious expressions, or it protects no peaceful religious expressions.
Therefore, I strongly contend that Americans under 21 have the absolute right, under the Lord and under the law, to drink to either the content of their heart, or the strength of their mind and body, whichever comes first. The egregiously high drinking age is a violation of the first amendment, and I would hope any court in the land, upon hearing this case, would agree.