If we get another one any time soon, it will all but guarantee another Assault Weapons Ban. Right now there still is a very good chance it won't happen. But if another mass shooting takes place we're finished. People don't act about guns and gun control. They react with emotion. Look at all the major gun laws that were passed since the 30's. All were knee jerk reactions to criminal events that unfolded shortly before. The National Firearms Act of 1934 was a direct result of fully automatic weapons being used by organized crime, along with the infamous "Motorized Bandits" of the 30's, like Bonnie & Clyde, Machine Gun Kelly, Baby Face Nelson, etc.
The Dodd Bill, (Better known as The Gun Control Act Of 1968), came out of repercussions of both Kennedy assassinations, along with the assassination of Martin Luther King. The Assault Weapons Ban of 1994 was a direct political result that came from the Long Island Railroad shooting that resulted in the death of Carolyn McCarthy's husband.
The tide in recent years has shifted against gun control in general, but that could change in a heartbeat. If one more of these type of shootings occur, and any type of semi auto weapon is used. I doubt that anything could stop another AWB, and perhaps worse.
The only thing that we have in our favor now is an enormous amount of people who are both buying these type of weapons and ammunition, and joining the NRA in droves. Along with the fact we now have a do nothing President. He's already pawned the job off to Joe Biden, in an effort to make him the political bad guy in all of this. One more mass shooting with a big body count will change that badly for gun owners. That is the way I see it. Your mileage may vary.