Semi-automatic firearms have been popularly sold to private citizens since the late-19th century. They are the most-popular design sold today and have clear constitutional protections. So, no, the president doesn't get to tell us we can't own them.
Jurisdictions that embrace the progressive soft-on-crime philosophy that was popularized after a handful of high-profile police-suspect interactions are fueling rising crime rates. American freedom is not to blame for this.