His analysis of the holes in the Gazette opinion can't really be improved on, so read it.
In the "Dan Quixote" post on January 12, when the Gazette first reported on McGee's bill in its news section, Montana Headlines pointed out that not only is I-153 probably unconstitutional, it is bad law.
Initiatives are first and foremost a way for the people to force issues into the system of making laws -- issues that legislatures can't or won't address. There is a legislative process in place to overturn initiatives, and it is there for a reason.
Do a little Gedankexperiment -- if Montana voters passed an initiative banning abortion (with the usual exceptions for extreme situations), would the Gaztte editors support or oppose a Democrat-controlled Montana legislature overturning it? Please.
As Crisp points out, the least disruptive way of dealing with a bad initiative is legislatively. Constitutionally, the legislature is the primary means by which laws are to be enacted.
Of course, the Gazette knows that a majority of the Montana Supreme Court (where any challenge to I-153 would end up) has, shall we say, the perception of obligations toward certain Democrat interests. Thus, it is understandable that they would prefer I-153 opponents to pursue this matter in the courts.