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.
While this is true, the exemption is generic and will likely encompass a large number of lobbying organizations, not just the NRA. From a National Review
Politico and others are reporting that the NRA has reached a deal to withdraw its opposition to the bill in exchange for an exemption for the NRA from its disclosure provisions. The exemption would apply to “organizations which have qualified as having tax exempt status under section 501(c)(4) of the tax code for each of the 10 years prior to making a campaign-related disbursement, that had 1 million or more dues-paying members in the prior calendar year, that had members in each of the 50 states, that received no more than 15 percent of their total funding from corporations or labor organizations, and that do not use any corporate or union money to pay for their campaign-related expenditures.”
Although I have no hard data to back this up, I suspect that this will also exempt some prominent left-wing organizations, specifically member-supported environmental groups such as the Sierra Club and the National Wildlife Federation. Furthermore, I foresee groups that don't quite
qualify for the exemption making a push to get themselves qualified. (For instance, an organization might try to increase its membership from ~800,000 to the magic 1 million mark by creating a "Junior Membership" that costs $5 instead of the normal $30 and doesn't include the magazine subscription.)
Future attempts to close the "loophole" will probably be politically difficult because the effort will be opposed on both
sides of the aisle.