After Newtown, NRA advocated required mass mental health testing [View all]

they supported mental health testing as a way to institutionalize people and by that means it would prevent them from purchasing guns.

they continued to oppose background checks and other requirements to purchase guns, so the mental health testing fails to do anything in most cases unless it locks people up.

the only other possible explanation is that they knew their argument was BS but it was all they had at the time and since they've lied in previous PR wars, why shouldn't they in this instance?