A candidate’s spouse has always played a significant role in presidential politics. They are expected to smile, look devoted, exchange adoring glances and hold hands in public. That was then, this is now. Bill Clinton has hardly played the shrinking violet. He has been an attack dog, a crowd-pleaser and, more importantly, the most formidable potential First La…Husband? in American history. And the Clintons’ unflagging tag-team attacks have definitely worn down Barack Obama. So it is time for him to unveil his secret weapon: Michelle Obama. Accomplished, articulate and fetching, she is everything that a First Husb…ur…Lady should be. But this week in South Carolina, she is something else: Black. Not the bright-skinned, mocha latte black of her bi-racial husband. Nope. A complexion that is wonderfully and gloriously black as the ace of spades. A clear signal to wary African-Americans in the south. It says that Obama is not only young and gifted. He is black. A black man who embraces his race. A black man who doesn’t think he is above marrying a woman who is a few shades darker. A black man who is totally authentic. It’s a message that white folks may never notice. But for black voters, it’s a message that speaks volumes.