The impact on politicians is most straightforward:
States are lining up against the Act, although some are on the fence about it. A strong showing from the public will not only let DHS know how we feel about it, but it will also be a boost in the undecided states -- and increase the momentum for a repeal in Congress. The commenting process isn't easy, and so legislators estimate that each comment represents the views of 1,000 people ... your voice matters a lot.
The other two require a bit of context for how the "rulemaking" process works. Briefly, once Congress passed Real ID in 2005 (with no debate, as a rider to a "must pass" spending bill ... but that's another story), DHS has the responsibility proposing a "rule" to implement the law. All proposed rules go through a public commenting period; the proposed rule can be adopted as is, or can be rejected. If rejected, it needs to be redrafted and sent out again for public comment. The current commenting process ends May 8.
And these kinds of commenting processes do work to kill bad laws. The example Deborah gave:
The more negative comments DHS receives, the less likely it will be that the rule will be adopted.... If that happens, we have another 30 or 60 days to try to convince Congress to repeal the law.
If no one says anything during the comment period, DHS will say that the public is fine with Real ID, and fine with all of the privacy invasive decisions contained in their draft rule.
The biggest one I've seen involved Secure Flight -- a passenger profiling system that the US wanted.
DHS and DoT published a draft rule in the Federal Register .... We commented it to death, we hit all of the press we could, and basically forced them to convene a committee (DHS put it together). A scathing report was issued, and guess what? Secure Flight was killed. It's still dead.
So yes, this is a difficult and somewhat obscure process ... but it's well worth doing.