As I said, the biggest part of "the others" are people who are not gun right advocates but generally don't want an overall ban. Just like in politics, the people who matter the most and the people who sway the elections are not on the right or left, but center. Because they are unaffiliated with either side and are unpredictable.
If the majority of population ever supports banning guns, 2A is out the window the next election cycle.
Neither you nor the dope-smoking socialists can afford to lose the support of the people in the middle.
So how do you see "not giving up on bump stocks", exactly ? For the majority of moderate people in the middle, it's an evil device designed to circumvent the law. How much of a fight are you willing to put up to defend it, and how much political capital / reputation are you willing to spend on it ? What public image do you want us to project ?
Winning is knowing when to dig in and fight, and when not fight a battle that's not worth it.
If they do it now, sure.
If they wait until there's a Democratic president and Democratic majority, they may succeed - if enough politicians feel that there will be no repercussions. Not necessarily in reversing 2A, but in severely curtailing it.
And this really depends on what the Joe In The Middle thinks. Thanks to that Joe, we today have far better gun laws than we did 20 years ago. Do you really want to push him the other way ?