Glee” wades into the gun-control debate on Thursday night, and by now, nobody should be surprised by the show’s politics. That said, there’s a moment in what’s otherwise a rather taut “very special episode” that illustrates why those who complain about liberal bias — an easily riled bunch as it is — occasionally have a point.

Without giving anything away, in the midst of discussing guns one of the characters refers to “gun yahoos,” citing those concerned President Obama is going to revoke their 2nd Amendment rights.

Obviously, such a mentality exists, and the reaction to Obama’s rather modest gun-control proposals in some quarters has clearly bordered on hysteria. Or as Jon Stewart put it on “The Daily Show,” “It looks like a ‘tyrant’ is anyone sworn to protect the Constitution that you didn’t vote for.”

That said, this wasn’t a CNN forum or the op-ed page of the New York Times. It was a frothy Fox dramedy known primarily for teen hookups and covers of popular songs. Yet if you tuned in hoping simply to enjoy the performance of “More Than Words” and happen to be part of the rather sizable contingent that believes the 2nd Amendment precludes any sort of gun-curbing legislation, you were lumped in with the “yahoos,” without any sort of pushback to the comment.

It’s a small example, granted, but emblematic of one of the most frequent gripes registered from conservatives about “liberal Hollywood:” Not the themed episodes or movies tackling an issue in overt fashion, necessarily (although they’re generally not fans of those either), but what amount to casual asides and throwaway lines they perceive as insults and attacks on their views. While such reactions are often overblown, it’s difficult to construe “yahoos” any other way.

Of course, this sensitivity has birthed groups devoted to letter-writing campaigns over any perceived slight, and at times a desire by networks to shy away from hot-button issues, which is hardly a solution. Someone like “Glee” co-creator Ryan Murphy has certainly earned the right to express himself within the context of his shows, in the same way writer-producer David E. Kelley frequently does. That’s also a strategy to keep shows interesting and relevant as they age.

Nevertheless, execs and producers shouldn’t be surprised when gun-rights advocates — or some other constituency feeling affronted in a similar manner — get their backs up over such moments, filing them away as evidence of Hollywood’s disdain for them.

“Glee’s” effort to join the current debate is timely, promotable and even laudable. But in these polarized, partisan times — where ideologues are always on the lookout for something to rally the base — there’s more at work here than the inevitable “Shut up and sing” response. Because by labeling those with whom it disagrees “yahoos,” the show has given gun advocates the last thing they need: More ammunition.