On the morning the NRA’s convention kicks off, Meghan McCain sounds off on her right to hit the shooting range—and why it’s so important to defend the Second Amendment. In the days after my dad lost the election, my brothers and I went to shoot rounds at the local shooting range. Partly because—as anyone who knows how to use a rifle and can do so safely understands—doing so is hugely stress-relieving, and partly because, we half-joked, it might mark the beginning of the end of our Second Amendment rights under the Obama administration. Now I admit we probably thought as...