Did Biden plagiarize a line from Bill Clinton's 2008 convention speech?

Last night, Vice President Joe Biden said, “The 21st century is going to be the American century. Because — because we lead not only by the example of our power, but by the power of our example.” At the 2008 convention, Bill Clinton said, “People the world over have always been more impressed by the power of our example than by the example of our power.”