It is time conservatives speak out and demand respect for their civil rights. The U.S. Department of Justice has taken a position in the D.C. gun ban case before the U.S. Supreme Court that puts one of our constitutional liberties at risk.

My colleague Sandy Froman recently wrote an opinion piece to protest the amicus curea brief the Justice Department filed on Friday in the D.C. gun ban case, District of Columbia v. Heller. In her Townhall.com column, she explains that the DOJ’s position includes only halfhearted support for the Second Amendment. If the Supreme Court were to adopt the position recommended by the Justice Department, it would imperil our civil right to keep and bear arms.

When the Justice Department filed its brief in the case, it took a middle-of-the-road approach. The brief says that the Second Amendment is a right for individual citizens. It denies the Second Amendment is a “fundamental” right, and says the Supreme Court should only give that right an “intermediate” level of protection.

It appears the Justice Department is trying to say this is a right that should be protected, but the level of protection should be low enough to allow government to broadly restrict or maybe even eliminate your ability to exercise that right. They try to split the baby of having a right but letting government do almost whatever it wants to that right.

The problem with splitting a baby in half is that the baby usually dies. If our rights can be regulated to the point that we can’t exercise them in our own homes, then they’ve been regulated out of existence.

So much for civil rights.

The Left refers to racial equality and voting as “civil rights.” But, civil rights are broader than that. Our civil rights are all the rights guaranteed by the Constitution. The Declaration of Independence tells us that government exists to protect our God-given rights, and the Constitution created our court system where those rights are vindicated.

There are three civil rights for which any attempted regulation should be looked at with great suspicion. They are religious liberty, political free speech, and the right to keep and bear arms.

Our country was founded by pilgrims seeking the religious freedom to worship according to the dictates of their own conscience, free from government dictates. The highest promise of free speech is that we may openly discuss the public issues of the day free of censorship or threat, so that we can hold our elected leaders accountable and replace those whom have failed to keep our trust.

And the right to keep and bear arms was put there so that we could provide for ourselves, defend ourselves and our loved ones, and have a last resort to defend freedom.

Laws curtailing any of those three rights should be looked at with the most skeptical and doubting eye, and we ought not to allow such laws to go further than necessary to achieve extremely important objectives. For example, as important as free speech is, it’s clear why the government must be able to stop television reporters from showing maps of troop locations and movements in overseas operations. Narrow rules are allowed where such life-and-death matters are at stake. But our civil rights can only be regulated in that minimal fashion, and only when absolutely essential. We never sacrifice our liberty.

Yet in the face of all that, the city of D.C. has a gun ban that forbids having a handgun or any loaded rifle or shotgun anywhere in your home. If you do, you’ll do more than pay a fine. You’ll go to jail.

This law plainly violates the Second Amendment, and ought to be struck down. A federal appeals court did just that, and now the Supreme Court has taken the case.

I am not a lawyer, but I have gotten solid information from some good lawyers at the American Civil Rights Union, in addition to legal perspective, from a couple of the best Supreme Court lawyers in the country.

They are gravely concerned about the Justice Department brief in the Heller case, saying that this could be a Trojan horse in the Second Amendment. They say that for various legal reasons if the Supreme Court were to adopt the position in this brief it would be toxic for gun rights in America. This lawsuit could go either way off the brief’s argument, but future challenges to firearm restrictions — no matter how severe — would likely fail.

This brief was a terrible mistake. Hopefully the lawyers in this case can persuade the Supreme Court to reject that argument, and give our Second Amendment civil rights the robust protection they deserve.

Mr. Blackwell, a fellow at the American Civil Rights Union and the Family Research Council, is a contributing editor of Townhall.com and a member of the NRA Public Affairs Committee.