There's the occasionally repeated point that arts tend to draw in people with radical ideas and/or marginalized agenda...
Which is total bullshit, btw. I have been around enough actors/writers/wannabes/artsy-fartsy types to know that their idea of "radical ideas and a marginalized agenda" is growing up misunderstood in a hick town just like the rest of us. While a willingness to offend/shock/shuck convention can foster some creativity, it rarely does so in a culturally meaningful way. Rarer still is the liberal play that pushes the envelope well.
What is the conservative stage equivalent of the first gay kiss, the first interracial kiss; the conservative stage equivalent of brilliant strung-out prophets and flamboyant, flashy colors and dancing and scantily clad ladies and gents?
Answer: Opera. Wagner in particular.
I can think of plenty of plays with conservative viewpoints. Everything from Oklahoma to The Music Man, where Marion, our gentle librarian, plays straight man to the wildly flamboyant Harold Hill. And what could POSSIBLY be more conservative than Our Town. But like most plays with a conservative viewpoint, most of those made me want to gouge my eyes out. Pulitzer Prize my ass.
Hmm... Well taken, but I think you're overestimating two things: the % of actors/writers/wannabes/artsy-fartsy types whose "idea of "radical ideas and a marginalized agenda" is growing up misunderstood in a hick town just like the rest of us" out of the whole, and the extent to which conservatives don't consider depicting the status quo/the "idealized" status quo as normal rather than "conservative." That is, Oklahoma and Music Man might be hopelessly conventional in the way they see society, but I think conservatives wouldn't view that as a "conservative" play at all. Which was part of my point -- the analysis of the leanings of plays and playwrights is trickier than the author even came close to implying. After all, it is easy to argue the caveman politics of many plays/art with a damsel in distress saved by a charming handsome leading man, and/or with a female lead whose three-dimensional characteristics consist of the dimensions of "hot", "young", and "coquettishly attracted to the male lead", but I find it hard to imagine most people counting them as "conservative" in a political way. Which, I guess, was part of the point I was trying to make: making plays that are about, celebrate, or depict that status quo or a by-gone age is "conservative" in the same way that, let's say, "Rent" is liberal -- Rent isn't quite a liberal message play, but rather one that emphasizes the humanity of and treats as normal a bunch of outcasts and supposed non-conformists; what liberal message does that present other than "We're queer, we're here, and we're having lots of sex"? But by accepting "deviant" lifestyles, it's defined as "liberal", whereas accepting "normal" lifestyles -- patriarchy, female frailty, traditional marriage -- isn't considered "conservative" by even many liberals (as long as the traditionalness and female frailty aren't oppressive; cf. almost all mainstream romantic comedies). Which, actually, brings me back to my other point I forgot about -- I'd say that there're plenty of liberal plays that DO push the envelope well; they're just ones we're not thinking of, because when you push the envelope well, the political message isn't plainly and simply spelled out. It's a rare play that is OBVIOUSLY a message play and is good, I think (not a play, but case in point: the movie "In the Heat of the Night.)
And you did quite call me out on Wagner, you're right, and not having seen "Our Town," I'll give you that one, but I pose two challenges to you.
1) All the plays you name aren't contemporary; especially Wagner and Our Town are from rather a bit back, such that one can argue that many pieces of work written over 70 years ago are going to appear/be "conservative," because they express viewpoints that have long since been out of vogue/refuted. "Taming of the Shrew" seems rather cretinous to me, and while it's false to suggest that sexism was accepted without question by all hundreds of years ago, it's not false to say that sexism was quite acceptable and accepted as reality by most. So riddle me this, D: name a contemporary conservative play. (I'm sure you can, I'm just curious what you'll come up with.)
2) Name a conservative message play. Which seems to be the hidden presumption of the NYT author, anyway -- that liberal plays look to advance the liberal agenda, ergo any "liberal" play is a liberal message play.
By the by, I think you're right that liberal message plays rarely push the envelope well, but I would argue that many plays that aren't WRITTEN to be message plays, liberal or conservative, DO push the boundary well. Rather like "The Half-Hour News Hour" or "Studio 60 on the Sunset Strip," the creators (conservative and liberal, respectively -- I just noticed that) missed the point in that comedy, especially, usually fails when its first master is a message. Its first master must be being funny -- THEN you can do the message. As with message plays, if you start with the goal of having a message, you'll have one, but it might be a shitty play. If you start with the goal of an excellent play/show, and then within that you wish to plant a message, you might get it right.
So my last long-assed-introductioned question: are there any deeply influential plays that *didn't* push the envelope? Or is it true necessarily that superlative excellence requires pushing envelopes (whereas pushing envelopes doesn't necessarily mean it's any good).