What do the cool kids wear to an election? In Minnesota, you've got to know.

Back in November, when the U.S. Supreme Court agreed to rule on the fate of Minnesota's voter-dress-code law, I wondered in a column whether I might run afoul of this peculiar statute by wearing one of our stylish Star Tribune T-shirts to my polling place.

Since I am employed by the Star Tribune as a tolerably hardworking "Opinion" journalist, oozing political attitudes from every pore "all day, every day," as the paper's mission statement puts it, it occurred to me that my employer just might be one of those "organizations" that possess "recognizable political views" — and whose insignia, state officials have decreed, are therefore unlawfully disruptive or intimidating when displayed by a would-be voter on Election Day.

I was trying to be facetious. But in the wake of the state's defense of its law during oral arguments before the Supreme Court at the end of February, I'm not at all sure I succeeded in exaggerating, or even equaling, the actual silliness of the state's rules.

To be sure, the state's lawyer, Daniel Rogan, under questioning by the justices, allowed as how he thinks a T-shirt bearing the text of the First Amendment would probably "be allowed" at a polling place under Minnesota law.

Expressing support for freedom of religion, speech and press would apparently not disrupt American democracy in the state's view (he thinks).

But when Justice Samuel Alito asked: "How about a shirt with the text of the Second Amendment?" Rogan sputtered: "Your Honor, I — I — I think that that could be viewed as political …" [and therefore not allowed].

The old-fashioned view of such matters was that state laws are supposed to conform to the U.S. Constitution, including, of course, the Bill of Rights. But now we learn that not all parts of the Bill of Rights pass muster equally under Minnesota law.

To back up, as I explained last fall, the law before the court, long on the books and not unlike election regulations in nine other states, is aimed at keeping electioneering and intimidation out of polling places on Election Day. It bans anyone from importuning voters at or near the polls to campaign for or against specific candidates, political parties or referendums on the day's ballot, even if only by displaying signs, posters, buttons, etc.

But the law goes further, prohibiting even more general "political" material and attire, such as "[a] political badge, political button, or other political insignia" of groups like the Tea Party or MoveOn.org with the aforementioned "recognizable political views."

The Supreme Court's review is the culmination of a seven-year legal battle over the constitutionality of this regulation, brought by the Minnesota Voters Alliance, an outfit critical of Minnesota's voting system. The struggle started when alliance executive director Andy Cilek wore a Tea Party T-shirt and "Please I.D. Me" button to the polls back in 2010 and was "temporarily prevented from voting."

Such delays are apparently all that happens to a voter who refuses to cover up words or symbols Minnesota election judges deem prohibited. The recalcitrant voters' names are also recorded for possible later legal action.

The mildness of these consequences inspired Chief Justice John Roberts at last month's oral argument to question the seriousness of the state's concern.

But Justice Elena Kagan had the answer to that. Like all the court's more liberal members, Kagan seemed favorably disposed to Minnesota's law and to its purpose of preserving "solemnity" and "decorum" in the polling place. Actually, the conservative Roberts as well as Justice Anthony Kennedy, often a crucial swing vote, also seemed impressed by the need for "decorum" on Election Day.

Anyway, Kagan thought she saw how the dress code law helps achieve polling place propriety:

"I assume," she said, "that the real work of this statute is being done by the fact that people know about it and so people just don't wear these things for the most part … people just approach the polling place in a different kind of way."

If you were looking for a textbook definition of the "chilling effect" on free expression overly restrictive laws are often faulted for creating, without actually needing to punish many transgressors, you could scarcely describe it more clearly than Kagan has here. Because of Minnesota's dress code, "people just approach the polling place in a different kind of way."

Right — leaving their stinking free speech outside.

In addition to the Second Amendment being rejected while the First Amendment was ratified, a T-shirt bearing the letters "NRA" would not be allowed "[t]oday, in Minnesota," Rogan declared.

How about a "Parkland Strong" shirt? he was asked.

"I would say that that would be allowed in," Rogan answered.

But a Colin Kaepernick jersey or an "All Lives Matter" shirt would be out, Rogan said.

"A shirt with a rainbow flag?"

A "#MeToo" shirt? Apparently that would depend on whether "that was an issue in … elections in that polling place."

One would have to travel to a precinct far, far away to find a polling place this year where issues of gender equality symbolized by #MeToo won't be "on the ballot" in some fashion.

What all these answers betray — apart from a "recognizable" hostility to gun rights — is a knee-jerk arbitrariness about what is "political" and what isn't. And on Election Day, as Rogan explained, thousands of individual election judges across the state apply their own standards.

It is frankly hard to imagine the Roberts court, with its strong record of defending even truly disruptive exercises of First Amendment rights, accepting this kind of cavalier denial of free expression. But who knows?

It surely would be tragic in our delicate day and age if American politics lost its "decorum."