From Public Policy Poling:

66% of Americans consider the United States to be a safe country, to only 23% who consider it unsafe. Perhaps as an outgrowth of that sentiment only 45% of voters support Trump’s Executive Order on immigration, to 49% who are opposed to it. Among those who do support it you have to wonder how well thought out their position is – by a 51/23 margin Trump voters say that the Bowling Green Massacre shows why Trump’s immigration policy is needed.

Emphasis added.