One-man shows are almost always about division. How else can one speaker get up the requisite dialectical steam to keep an audience interested? The most popular (and played-out) method is to talk about an identity-split—solo performers believe their private struggles with race, sexuality, and religion will rivet others to their seats, and they usually woefully overestimate our interest. But in “American Fiesta,” a relatively gentle example of the species, Steven Tomlinson has a bigger division in mind. In his scrupulously polite show, nothing less than the gulf between liberal and conservative, blue state and red, will satisfy him.

Mr. Tomlinson has a political fault line running through the center of his family. While he enjoys a blissful romantic relationship with a man named Leon in Austin, Texas, his parents struggle quietly with his “lifestyle choice” back in rural Oklahoma. It’s not that they don’t love their son, but Mr. Tomlinson’s father won’t let the couple share a bed under his roof. Once Leon and Steven announce their plans to wed in Canada, everything that has gone carefully unsaid comes roaring out at the dinner table. Will the older generation capitulate and attend the same-sex ceremony? Will their son forgive them if they don’t?

The stress drives our hero into the familiar embrace … of eBay. His chosen retail therapy is buying Fiestaware, the brightly colored Depression-era china originally manufactured for poverty stricken housewives. Now, each vivid bowl goes for $600, and Fiestaware has become a collectible cult, with attendant “bibles,” conventions, and online communities. Mr. Tomlinson milks every last metaphor out of his tableware — we hear about appreciating the cracks (just like people!), the color scheme’s almost primal appeal (just like the Homeland Security alert colors!), and, of course, its fragility (just like … you name it).

Mr. Tomlinson also takes on us a PowerPoint tour of the brain (designed by Jan Hartley), drawing attention to the bits of gray matter that respond to wants and needs. It should come as no surprise that the synaptic firestorm triggered by shopping looks just like the one set off by intense political feeling. While discussing his own fractured family, Mr. Tomlinson also wants to talk about the country, a place in which left-right divisions preclude reasoned debate. He comes up with a few quirky suggestions — such as declaring your prejudices to the IRS to get a tax break for eating with the ideological enemy — but largely stays content with snuggly, let’s-sit-down-together sentiments.

Of course, no matter how delicately he puts it, Mr. Tomlinson has resolved his own situation with a pretty brutal ultimatum. He couches it in terms of acceptance, and appreciating one another’s flaws, but Mr. Tomlinson hammers his way through parental prejudice with a threat. Either the family can accept Leon as Steven’s husband, or he’ll never come home again. That’s not accepting the others’ chipped edges; that’s smashing the crockery and lucking out when it mends so well. Now how exactly do we apply that to the country at large?

Mr. Tomlinson never gives us an answer, and addresses us with patronizing, schoolmarmish clarity. Director Mark Brokaw keeps him moving about, symbolically placing the (anti-big government) Number Four Red mixing bowl next to the cobalt one, which represents the abortion-rights movement. But what we really needed was some unbridled emotion, some dramatic rage or delight. We don’t need another lecture; we need a bull in the china shop.