They were there to make a point.
Their intended point was to indicate that President Obama is in the process of "taking away the people's rights," that health care reform was just the first step to curtailing the freedoms of all Americans.
Ludicrous, I know.
Their unintended point was to show, unequivocally, that reactionary elements in this country are mobilizing. They have been given life by the election of the first African-American President, and simmering hostility, for years kept behind closed doors, is now out in the open. They have also been given a voice by news outlets, using the opportunity to gain fame for themselves and a TV/radio audience for their platform. They know how to play the game, and have played it well.
Now, the Second Amendment has been analyzed and interpreted since its inception, but the intent of the amendment was clear: the Founding Fathers felt that in order to ensure the safety of the fledgling United States, and to make mobilization in case of invasion by a foreign power easier, that American citizens would be entrusted with the right to keep their arms. It was a warning to other nations, that attempting to attack the United States on its home soil would be folly, given the number of armed citizens capable of forming local militias in short order. George Washington had already proven that militiamen and citizen soldiers could, in time of war, been honed into an effective fighting force.
Two hundred and twenty plus years later, the idea that any nation would attempt a direct land invasion of the United States is considered fantasy, given the strength of our armed forces, the weapons at our disposal, and above all, our nuclear deterrent. The armed citizen militia is the very last line of defense, and if it comes to that, that would tend to indicate that America has suffered a mortal blow.
So now the need for an armed citizenry is less pressing, but still, the right is woven into the fabric of the Constitution, specifically as part of The Bill of Rights. While an amendment can be repealed or even superseded by a new amendment, The Bill of Rights has taken on a stature that makes it seem inviolate, as if the mere suggestion that any of its provisions be struck down is madness. For better or worse, the Second Amendment is here to stay, and it's more important than we learn how to handle it, than to bemoan its existence.
For those who are decent people, who take the use and ownership of weapons seriously, and have taken great pains to handle their weapons with respect, the idea that gun ownership should at least be regulated, should not cause them any great concern. Yet, gun groups, most notably the National Rifle Association, stand staunchly against the idea of registering and regulating firearms, as if it some sort of affront, as if they are being told "we don't trust you." It is a peculiar stance for an organization to take that says it is protecting the right to bear arms, because by doing so, they allow firearms to fall into the hands of those who most decidedly should not have them, weakening their position. Just as there are laws that say yelling "Fire!" in a crowded theater is not free speech (per the First Amendment), it would seem to make sense that saying convicted felons cannot own guns, or that guns are not allowed within city limits, would be just as constitutional, per the Second Amendment.
This fetishizing of firearms, coupled with the idea that the basic rights of Americans are under siege, is leading to an inevitable collision, which will not go well. That these men brought weapons within easy range of the President is disturbing, of itself, but not nearly so anxiety-producing when one remembers that our President is escorted everywhere by one of the most elite paramilitary forces the world knows, the United States Secret Service. No doubt a person carrying an overt weapon was identified as a potential hostile and treated accordingly, and would not be given the chance to create mayhem.
The flip side of that is that while an obvious firearm would be engaging the attention of authorities, an unobtrusive weapon could still be in the crowd. It's never the devil you know, but the one you don't, that inevitably catches you off guard. The presence of those weapons was a clear sign that tensions are escalating, and that someone with ill intent may very well try to assassinate the President, given an opportunity. This ramps up the tension further, to the point that soon, a person carrying a legal firearm to a rally or protest where the President is scheduled to be, may find themselves on the short end of a killing shot for making a gesture that, in a split-second, could be interpreted as brandishing their weapon.
It is fine to make your voice heard, to protest policies you feel are not in the best interests of all Americans. It should not require a gun to make the point.