Any call for banning firearms of any description is based on emotional appeal. After all, emotional appeal, not facts, is what garners votes and, folks, votes and money is what it is all about, plus, of course, power.
When the politicians get the votes and the money, then they get the power. For the majority of people, facts are "boring", but emotional appeals hit home. When you get X number of people foully murdered by someone using a firearm, you have a basis for a major emotional appeal. Never mind that X to the umpteenth power were killed the same day by automobiles. You'll never hear an emotional appeal to ban those "assault" automobiles, will you?
Then there is the other factor that comes into play about calls for banning firearms; you cannot have absolute power over an armed populace. Therefore, even with all the votes and money, there is a limit on the politicians' power and they do not like that. Only when you have a disarmed population can you exercise almost absolute power.
Please note that I did not differentiate between political parties. Any one of them, given the right circumstances, would seek that absolute power.
Please tell me that I am completely out of the ballpark on this one. And then show me how I am wrong.