Americans generally support more federal gun control. They also believe it won't really help?
Pew Research analysis (click link). Basically people "get it". With 400 million guns in circulation, no amount of gun control is going to move the dial materially.
That doesn't mean that gun control is a bad idea, just that if we want to reduce homicides and gun violence, as we done in the late 1990s the answer lies in smarter and better law enforcement, which requires public support of law enforcement (and reforms to such).
Statistically speaking, the homicide rate in this nation is driven by gang violence. When we address that issue we directly address homicides.
BTW: Mass shooting are horrible, dominate the headlines but represent less than 1% of homicides.