It also says a lot about priorities. "Sure I am willing to make a law that goes against women's rights and makes abortion and pregnancy in general costlier and more dangerous... As long as motorcycling laws are adjusted at the same time. I mean who care's what happens to some women as long as my motorcycle needs are satisfied."
I think this law is a perfect example of shoehorning.
Pretty much. Why, exactly, isn't it illegal to attach unrelated crap onto bills?
Basically because the legislature has an old, old right to legislate about whatever the hell it wants. (In the British system, the various Houses of Parliament always introduce a pro forma bill before considering the Speech from the Throne to remind the monarch that while she might have convened Parliament, they can consider any matter they want, not just the monarch's agenda.)
But why does that mean they can tie two completely unrelated things together inseparably? Legislate whatever you want, but do it one thing at a time.
Basically, the legislature has to be able to consider and pass or reject whatever bill it wants, no matter what that bill contains. Courts can later strike parts of it down, and the executive can veto it (or parts of it, depending on the locale), but it's getting into a legal mess to determine what bills can and cannot be considered if someone (and what someone is that?) has to determine what's "related" and "unrelated".
(I should note for fairness' sake that the Parliament Act 1911 in the United Kingdom does have a provision for the Lords to be unable to overly delay money bills, where the Speaker of the House of Commons certifies what bills are money bills or not--basically, they have to have nothing at all about anything other than appropriations. However, the Speaker of the House is a nonpartisan figure, to the point where s/he is traditionally unopposed in elections.)
