Leg history of the 1927 Federal ban on mailing handguns

Interesting. I had wondered when the average law abiding citizen had started the practice of going about unarmed. Here, we see that it was still common in 1927, but that there was a distinct group attempting to discourage it. Indeed he comes right out and says that as long as the law abiding do it, the lawless will as well. Want to guess the political party the good Senator represents?