Now subtracting emotion from the left's arguement on the issue, the AR 15 is no different than any other semiautomatic weapon, be it rifles or pistols. Looks mean & military, but it functions just like any semiautomatic weapon.....1 pull 1 bullet, that's it. NOT a military assault rifle, as that requires the option of automatic, which has been banned for civilian use for decades now.
The ease of reloading and decreased recoil make it a perfect DEFENSIVE weapon, especially for women and short statured folks. Not to mention that these rifles are NOT the choice or most murderers, as that'd be semiautomatic handguns, which can fire JUST as fast, and reload JUST as easily.
Being an American, I'll leave it to the individual and freedom of choice to determine for themselves if they want one or deem to need one. But don't be surprised if leftists masquerading as folks who simply "just know better", erroneously claim they know better what you need, and more to the point, don't need.