Obama's eloquent expression of exceptionalism in Selma

This past Saturday, President Obama spoke in Selma, Alabama, marking the 50th anniversary of "Bloody Sunday"—the assault by Alabama state troopers on marchers from Selma to Montgomery for equal voting rights for African Americans.

His speech is remarkable for many reasons, but one of the things I find really remarkable is that it ranks as a singular example of presidential exceptionalist rhetoric.

There's nothing new in all that. We've come to expect our presidents to use exceptionalist rhetoric in their speeches. Ronald Reagan was particularly skilled at portraying America in exceptionalist terms, being fond of quoting Thomas Paine from Common Sense, who famously wrote of Americans, "We have it in our power to begin the world over again." He also liked to use Abraham Lincoln's descriptor of America as the "last, best hope of earth," although Reagan often substituted mankind for earth in his use of the phrase.