Nancy Pelosi is warning that, if Trump declares an emergency over the border, a future Democratic President could declare an emergency over gun violence. This argument is intended to frighten Republicans from taking action to prevent millions more potential Democrats streaming from Latin America into the United States.

Republicans should not let themselves be frightened. A future Democratic President could declare an emergency over gun violence, regardless of what Trump does. Indeed, dozens of national emergencies have been declared by prior Presidents. It’s not as if Democrats are in the habit of waiting for Republicans before seeking to expand government power.

And Trump will not be arguing that, because he has declared an emergency, he can now do whatever he wants. He will argue that, because he has declared an emergency, specific statutes previously enacted by Congress give him the authority, by their terms, of undertaking construction without any additional authorization from Congress. This is a question of statutory construction, not a question of the Constitutional limits of presidential power. And should a future President seek to begin grabbing guns on the basis of a declared emergency, he will quickly be reminded of what the Second Amendment means.