If you're still wondering why tea-party conservatives are so far removed from the American mainstream, if you want to understand why they comprise a mere 21 percent of the citizenry, look no further than the farce that played out yesterday on the streets of Washington.

I'm not even talking about the spectacle of Ted Cruz protesting the government shutdown (which undoubtedly inspired George Orwell to not only spin in his grave, but to start writing a new book about the debasement of political rhetoric). I'm not even talking about the tea party's "Million Vet March" that drew no more than a thousand. I'm not even talking about the IQ-plunging participation of performance artist Sarah Palin.

No, I'm talking about the rally outside the White House, which featured the flaunting of the Confederate flag.

That took real genius, to wave that noxious symbol of racial oppression at a building occupied by the nation's most prominent black family. Yeah I know, it was only one flag - but how noteworthy it was that nobody in the crowd demanded that the guy furl it and remove it. Nope, the flag stayed front and center. And what better way to remind mainstream Americans that the Republican base has become a last-ditch refuge for angry white people?

Naturally, tea party defenders stormed Twitter yesterday to defend the flag's presence. They oscillated between two arguments: (1) that the flag isn't about slavery at all, that it's just a benign symbol of Southern heritage; and (2) that, OK, even if the flag is about slavery, it doesn't represent the tea party movement as a whole.

Let us demolish those arguments in sequence.

As one tea party tweeter insisted (and his view was echoed by many), "The truth is, the Civil War was not about slavery," and neither was the flag. Really? Hundreds of thousands of Confederates didn't fight under that flag, and kill fellow Americans, for the cause of keeping human beings in chains? I have always thought that was the truth - especially after reading actual Confederate documents.

For instance, Article I of the Confederate constitution - codified a month before the war began - declaring that no law shall ever be enacted "impairing the right of property in negro slaves." For instance, the prewar speech by Confederate vice president Alexander Stephens, who declared that the rebel government's "foundations are laid, its corner-stone rests, upon the great truth that the negro is not equal to the white man; that slavery - subordination to the superior race - is his natural and normal condition." For instance, President Jefferson Davis' 1863 response to the Emancipation Proclamation, where Davis insists that "the day is not distant when the old Union will be restored with slavery nationally declared to be the proper condition of all of African descent."

I did a story 10 years ago about Georgia's "flaggers," people who thought the Confederate flag was just a paean to Southern culture. ( I guess they missed VP Stephens' declaration that slavery was the "foundation" and "corner-stone.") The best retort came from Tyrone Brooks, a state legislator who knew the history. He told me, "Racism is the foundation for their movement. After all these years, you'd think they'd be amenable to putting the Confederate era in a museum, in its proper context. But for these people to continue to promote (the flag) - knowing what that emblem means today - are they suffering from amnesia, or are they just ignorant?"

Probably both. But, thanks to Jefferson Davis and his crew, it's tough for today's slavery deniers to contest the factual 1860s.

The fallback position yesterday was that "the media" unfairly spotlighted the pro-slavery banner in order to smear the tea party movement. As one tweeter sarcastically typed, "Give liberals this: They figured out that the one clown with a Confederate flag on Pa. Ave. is the true leader of American conservatism." And another concurred, "Good for the media. They've finally found the grand mastermind of all conservative politics: some random jackass with a Confederate flag."

The flag guy may have been random, but his flag was actually perfect for a tea party rally. As I wrote in 2010, the whole tea party ethos can be traced back to John C. Calhoun, the South Carolina senator who inspired the Confederate treason with his doctrine of "nullification," the belief (long since invalidated by the Supreme Court) that states can choose to defy federal laws and decrees they don't like.

Much the way Calhoun inspired the outnumbered Dixie states to resist the anti-slavery movement - and ultimately, to reject Abraham Lincoln as the legitimately elected president, defying the will of the majority - the tea-partying Republican base has copped the same attitude toward Obamacare. And that was the trigger for the government shutdown, the daft nullification notion that an outnumbered minority can rule the roost no matter what the majority wants, no matter what the voters decided, no matter what the Supreme Court ruled.

But here's a parting tip for the tea partyers: If you ever hope to extend your appeal beyond your ideological cocoon, if you truly want to convince mainstream Americans that health care reform is horrible, do yourself a solid. Don't wave the Stars and Bars at the first black president. A tin ear for politics makes you deaf and dumb.

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