>After a school shooting in California, in 1989 George W Bush banned import of semi-auto rifles and began moves for an Assault Rifle ban. Presidents Ford, Carter and Reagan all wrote to the House supporting banning of assault rifles. Gallup polls suggested that over 75% of citizens supported such a ban. It still took until 1994- 5 years- for an Assault Weapon Ban to be passed with a 10-year sunset provision, meaning it expired in 2004. At that time analyses confirmed that any reduction in firearm violence from the ban was too small to be measured.
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>Another 14 years goes by and now assault rifles again are under examination, with people marching and blaming current politicians including current POTUS for not protecting them.
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>Perhaps people might ask what happened in the 14 years since the previous ban expired in 2004 which not even CNN can hope to pin on Trump, and why people believe another ban will make any difference if the previous one apparently made none?

But it did make a difference. Out of the 25 worst mass shootings (fatalities > 8) in the US since 1984, 15 occurred since 2004 (and only 3 during the ban).
However, in your stats, you're ignoring an important aspect: the worst case scenario, in which one individual armed with a weapon of war can cause a tremendous number of fatalities. Lately, this has become more and more relevant. Also, such a scenario is also very difficult to contain. In many cases, it involves a SWAT team, at which point the scene becomes virtually a war zone.
There are other factors than just simple statistics. Awareness is one of them. According to a Colt employee, sales of AR-15 rifles began rising after the school shooting in Stockton, CA in Jan 1989, before which, many American gun-owners were not interested or didn't know about the option of owning a semi-automatic weapon.
Things are changing. The legislation should reflect that. Public opinion already does. So far, we have seen only an increasingly more virulent rhetoric by the NRA, and "thoughts and prayers" from the politicians while pretending to defend the 2nd Amendment. Trump is not even relevant. He lost all credibility on this subject, anyway.
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