WASHINGTON -- Presidents are judged not only by the things they do but also by how successful they are in influencing the actions of the presidents who follow.
Leaders who want their achievements to endure know their task includes changing the terms of the national debate and leaving behind an intellectual legacy that shapes how future generations see the country and its possibilities.
Franklin D. Roosevelt accomplished this. So did Ronald Reagan. President Obama traveled Wednesday to Knox College in Illinois to give the speech that launched his effort to join them. It was where, in 2005, he originally laid out his philosophy of government.
Obama is making this bid in the face of a political culture that is far more cynical than it was in the days of FDR or the Gipper. He confronts adversaries determined to move the country in exactly the opposite direction from the one he would have it choose. And up to now, the president has been foiled or distracted whenever he has tried to focus the public conversation on reversing rising inequality and restoring social mobility.
So why should his latest effort be any different? Here are three reasons.
First, Obama and his advisers have learned from past failures. Earlier speeches along these lines came and went, barely causing a ripple in the public's consciousness. This time, the president is embarking on an eight-week campaign to keep his themes at the center of the debate. He wants to bend the news cycle rather than bow to it.
By giving a series of addresses that include specific proposals -- some old, some new -- he hopes to grab the public's attention, and the media's. His grass-roots operation will mobilize supporters to talk up these themes with their neighbors. Whatever else it is, this campaign is not a one-off.
Second, he will be speaking to a country that's fed up with the mean, narrow and pessimistic tone emanating from a capital locked in what Obama called "short-term thinking and stale debates." The president's critics have said over and over that he needs to "go big" and push the system beyond itself. Even his friends have been frustrated at his difficulty in seizing the initiative and confronting obstructionist opponents. He appears to have listened.
But the most important reason this offensive has a chance is that it goes to the heart of why Obama got elected in the first place and then won re-election. A substantial American majority just doesn't buy the ideas that Obama forcefully rejected: that "inequality is both inevitable and just" and that "an unfettered free market without any restraints inevitably produces the best outcomes, regardless of the pain and uncertainty imposed on ordinary families."
In describing his priorities, Obama's language was plain but direct: "Good jobs. A better bargain for the middle class and the folks who are working to get into the middle class. An economy that grows from the middle out. ... That's where I'll focus my energies -- not just for the next few months, but for the remainder of my presidency."
"Middle out" is the key concept. Since the Reagan era, conservatives have enjoyed enormous success in making supply-side economics -- the belief that wealth flows to everyone else from the economy's commanding heights -- a powerful, underground default position. A corollary: Government can do little to make the nation richer other than cut taxes and reduce its own reach.
The alternative view is, as Obama put it, that "growing inequality" is "not just morally wrong; it's bad economics."
"When middle-class families have less to spend," Obama insisted, "businesses have fewer consumers. When wealth concentrates at the very top, it can inflate unstable bubbles that threaten the economy."
In the long history of the country, concentrations of wealth and income always have perverse effects. Broadening our nation's winners' circle, on the other hand, has always been the best strategy for sustainable growth. We need to acknowledge this once again.
There is more Obama needs to do to make his case for the specific steps Washington can take to restore shared, robust prosperity. He will have to beat back the forces that would continue to shrink government through a sequester that is making the recovery slower than it should be.
But this time, he cannot let himself be sidetracked. With 1,276 days left in his presidency, he chose to draw a clear line and start a big argument. His place in history will hang in large part on whether he can win it.
E.J. Dionne is a columnist for The Washington Post Writers Group.