This isn't the first time the Constitution has been invoked by a social movement. Abolitionists, feminists, Dixiecrats and the civil rights movement have all appealed to the Constitution, says Akhil Amar, who teaches law and political science at Yale.
"Dr. Martin Luther King actually says, 'I'm here to redeem the Constitution, it actually does say equal, and we're not doing equal,' " Amar says. "And now we're seeing a populist movement on the right, and both of them are claiming a constitutional legacy."
But these days, says Amar, the grass-roots debate over the true meaning of the Constitution is a little one-sided. "I think it's a mistake for folks on the left to concede the Constitution rather than claim it as their rightful inheritance," he says. "If one side is claiming it, and the other side is not, I think that the side that claims it has a huge advantage in the culture wars."
King's exact words, in the "I Have a Dream" speech:
In a sense we have come to our nation's capital to cash a check. When the architects of our republic wrote the magnificent words of the Constitution and the Declaration of Independence, they were signing a promissory note to which every American was to fall heir. This note was a promise that all men, yes, black men as well as white men, would be guaranteed the unalienable rights of life, liberty, and the pursuit of happiness.
Craig McPherson, a Republican congressional candidate in Kansas who is sympathetic to the tea party movement, invoked those words in a defense of the movement.