I was just talking to Nat last night about how one progressive president like Teddy Roosevelt can make a long-lasting difference. Today, historian David Greenberg explains for Slate why so many politicians invoke part of TR's message today, and why his "Conservative Progressivism" is dead:

The alignment of the political parties along ideological lines has also created a bloc of independent voters who aren't thrilled with either party's platform. Ross Perot and John McCain supporters and other "disaffected" voters dislike both the Republicans' coziness with big business and the Democrats' lack of mettle. One reason for all the TR talk, then, is a wish to reach this independent center, once occupied in part by liberal Republicans, by appropriating Roosevelt's willingness to stand up [to] today's too-powerful trusts while adopting a muscular language of virtue. Those who can pull off this trick in the coming months and years may win more than the battle for TR's legacy. They may get themselves elected.