My guess is that he or she is saying that it's reasonable in both cases to require ID.
It’s only when you sell guns as a dealer that you are required to get ID and whatnot from the purchaser. (Even then, there is no penalty for BUYING the gun without ID; the penalty attaches to the SELLER.)
If it is not reasonable to demand an ID to blog or to vote, it is not reasonable to demand an ID to obtain arms.
If asking for ID to buy a gun is reasonable, then the argument of whether it’s reasonable to ask for ID to vote can’t be one of principle, but has to be one of degree.
I think of it this way: If you think that you're being unconstitutionally prevented from buying a gun because you don't have an ID you can at least vote for people who would change that. If you can't vote because you don't have an ID, though, you're SOL.
Edit: The second amendment even refers to "well regulated", which to me seems to imply that the intent was to, well, have some regulation of the matter.
lutorm's comment: "Voting is a constitutional right" (implying that is isn't OK to require an ID)
sneak's comment: "purchasing a firearm" (clearly a constitutional right, so it isn't OK to require ID to purchase one???)
That is perfectly relevant. What sneak's comment does is point out that lutorm's argument implies that we can't have an ID requirement to purchase a firearm. Since this conclusion seems a little crazy, it suggests that lutorm's argument is no good.
I'll add that at least for presidents, the constitution only makes voting a right for 538 specific people. States are not required to let the rest of us participate. Voting is clearly not more of a constitutional right than firearms.
An example: it’s legal to “keep” a pre-1986 machine gun but it’s not legal to obtain a new one for most people in the US.