You mean in the next year or two, or for all time? Because an exemption given today to buy the NRA's silence can be attacked tomorrow as a special loophole and taken away.
You seem to be assuming that the NRA opposing the legislation would kill it; which isn't a given. The Democrats have 59 seats in the Senate and a strong majority in the House and there are no shortage of people who think the Citizens United
decision was a bad one - in fact, I've defended the Citizens United
decision with fellow gun owners HERE on this forum.
If the NRA has a sure thing, should they risk it? And what level of certainty should they have before they do?