One of the big arguments about pushing the HB1926 route is that it runs into problems with Article III, Section 3, which says:
No bill shall be passed containing more than one subject, which shall be clearly expressed in its title, except a general appropriation bill or a bill codifying or compiling the law or a part thereof.
The short answer is there’s a pretty good case to be made for constitutionality, but that it’s not a slam dunk. The case law on this goes back more than a hundred years, and there’s enough of it that our opponents could find an argument to make. But there’d be a very strong case favoring Castle Doctrine’s constitutionality. A more recent case, you get quotes like this:
In broad terms, Article III’s aim was to “place restraints on the legislative process and encourage an open, deliberative, and accountable government.” City of Philadelphia, 838 A.2d at 585 (quoting Pennsylvania AFL-CIO ex rel. George v. Commonwealth, 563 Pa. 108, 757 A.2d 917, 923 (2000)). More specifically, Section 3 was designed to curb the practice of inserting into a single bill a number of distinct and independent subjects of legislation and purposefully hiding the real purpose of the bill. City of Philadelphia, 838 A.2d at 586. Related thereto, the single subject requirement prohibits the attachment of riders that could not become law as is, to popular legislation that would pass. An additional benefit of the Section 3 requirements is that there will be a greater probability that a bill containing a single topic will be more likely to receive a considered review than a multi-subject piece of legislation. Id., citing Millard H. Ruud, No Law Shall Embrace More Than One Subject, 42 Minn. L.Rev. 389, 391 (1958)(offering that an additional purpose served by the one-subject rule is to facilitate orderly legislative procedure). As we indicated in City of Philadelphia, the single subject requirement proscribed the inclusion of provisions into legislation without allowing for “fair notice to the public and to legislators of the existence of the same.” *296 City of Philadelphia, 838 A.2d at 587. Thus, reasonable notice is the keystone of Article III, Section 3.
Emphasis mine. I think this would tend to favor Castle Doctrine being constitutional, since legislators were given fair notice as to what they were voting for, and what was in the bill. You also have this from a footnote:
While recognizing the importance of Section 3, we acknowledged that bills are frequently subject to amendments as they proceed through the legislative process and not every supplementation of new material is violative of the Constitution. Thus, “where the provisions added during the legislative process assist in carrying out a bill’s main objective or are otherwise ‘germane’ to the bill’s subject as reflected in its title,” the requirements of Article III, Section 3 are met. Id. Article III, Section 3 must have, however, some limits on germaneness, for otherwise virtually all legislation-no matter how diverse in substance-would meet the single-subject requirement, rendering the strictures of Section 3 nugatory. As stated by our Court in Payne v. School Dist. of Coudersport Borough, 168 Pa. 386, 31 A. 1072, 1074 (1895), “no two subjects are so wide apart that they may not be brought into a common focus, if the point of view be carried back far enough.” Thus, defining the constitutionally-valid topic too broadly would render the safeguards of Section 3 inert. Conversely, the requirements of Section 3 must not become a license for **396 the judiciary to “exercise a pedantic tyranny” over the efforts of the Legislature. City of Philadelphia, 838 A.2d at 588 (citing Estate of Rochez, 511 Pa. 620, 515 A.2d 899, 902 (1986)). Indeed, “[f]ew bills are so elementary in character that they may not be subdivided under several heads….” Payne, 31 A. at 1074.
Emphasis mine again. So the Courts have said it can’t be read so broadly as to be meaningless, but that it is not an excuse for the judiciary to “exercise a pedantic tyranny” over the efforts of the Legislature. Given that these two subjects in HB1926 both deal with criminal law and criminal procedure, and self-defense can be tangentially related to kidnapping, I think there’s a pretty solid case that can be made that HB1926 is constitutional.