American history is defined by those moments that signal a divide between all that went before them and all that followed them.

Never had a candidate for national office spoken so frankly about race in America as Barack Obama did Tuesday in Philadelphia.

Except maybe once.

A hundred and fifty years ago, another lanky Illinois lawyer gave a speech that changed the way Americans talked about racial issues of their day.

Abraham Lincoln’s “House Divided” address, with which he accepted a U.S. Senate nomination in 1858 (he lost) changed the national conversation on slavery and, two years later, Lincoln was on his way to the White House.

Barack Obama planted one of those rhetorical markers in our landscape on Tuesday with his “More Perfect Union” speech near Independence Hall.

The address was meant to dampen the rising criticism that has attached itself to the senator’s campaign since video clips of race-baiting remarks by his Chicago church’s former pastor, Jeremiah Wright, began circulating in the past week.

But instead of offering a simple exercise in damage control, Barack Obama chose to place his response to Jeremiah Wright’s comments in a wider consideration of race in America - and the results were nothing short of groundbreaking.

Barack Obama - like Abraham Lincoln 150 years ago - wrote this historic address himself, completing the final draft Monday night.

He unequivocally repudiated Jeremiah Wright’s extreme rhetoric, but what is truly radical about Barack Obama’s analysis was his implicit demand that all Americans accept the imperfections of each others’ views on race.

Embedded in such acceptance is the seed of that “more perfect union” toward which this country - unquestionably great but imperfect - must strive.

Continue reading in the Los Angeles Times …