President Obama's eulogy for five Dallas police officers on Tuesday was an eloquent plea to Americans to acquire "a new heart" – a new empathy toward others across the racial divide. But the speech was remarkable for another reason: Rarely has a president talked so bluntly about the limits of his ability to bring about the changes he seeks.
"It is as if the deepest fault lines of our democracy have suddenly been exposed, perhaps even widened," Obama said. "Faced with this violence, we wonder if the divides of race in America can ever be bridged.
"We must reject such despair," he insisted, while acknowledging that he wasn't sure how effective his exhortations could be.
"I've seen how inadequate words can be in bringing about lasting change. I've seen how inadequate my own words have been," he said. "I confess that sometimes I, too, experience doubt."
Even though his presidency still has five months to run, a subtext of Obama's message was: I can't do much to fix this problem any more – if I ever really could. I'm speaking now, to all sides, to try to keep violence from spiraling. But in the long run, it will be up to others – citizens, police officers and mayors – to heal their communities. National politicians aren't likely to be much help.
And that part of his message was sadly correct.
In an era of partisan polarization, the problem isn't merely a deficit of great leaders capable of binding the nation together; it's also a shortage of citizens willing to listen.
Ever since the tenure of Ronald Reagan, an increasing number of Americans have tuned out presidents of the opposite party.
According to the Pew Research Center, only 14% of Republicans approve of Obama's conduct, compared with 80% of Democrats.
That's a record high in polarization – but the previous record was held by Obama's predecessor, George W. Bush, who was supported by only 23% of Democrats.
We still expect our president to act as a chief of state – a national unifier and, in times of tragedy, a national consoler – but we've made the job harder than before.
It's even harder in an election year, which sharpens partisan reflexes and tempts politicians to ignore the better angels of their nature (if they have them). This year, both major presidential candidates are focused on turning out their party's base supporters, not reaching across the center – which makes polarization sharper still.
Democratic candidate Hillary Clinton has issued a series of awkward statements on recent events, first expressing solidarity with the families of black victims of police violence, then expressing support for police forces.
Republican candidate Donald Trump briefly adopted a strategy that – by his standards – was statesmanlike: Silence. Then on Monday, Trump edged back into the issue, declaring himself "the law and order candidate" and blaming Clinton and Obama for racial division.
Some Republicans indulged in what can only be called acts of political arson: former New York Mayor Rudy Giuliani, who said Black Lives Matter protesters "put a target on police officers' backs," and Rep. Steve King, who said the Dallas shooting stemmed from Obama's "anti-white" attitudes. (There were black hotheads, too, of course, but they haven't been elected to high office.)
And there it was: the false dichotomy that Obama has struggled to break – the notion that you can support either the police or the grievances of black citizens, but you can't support both.
As America's first black president, Obama suffered from inflated expectations from the start. Many of his most fervent supporters – and many skeptics, too – hoped he could make major progress in healing the racial divide.
But there's even a racial divide on how well he did.
A Pew Research Center study released last month – before the recent shootings – found that 51% of black Americans think Obama made progress on race. Only 28% of white Americans agree, and 32%, think he made race relations worse.
Last week, musing to reporters about his legacy on race relations, Obama sounded philosophical. He said he hoped his children and grandchildren "can experience a country that is more just…. That's not going to happen right away -- and that's OK. We plant seeds, and somebody else maybe sits under the shade of the tree that we planted."
More than 300 years passed between the introduction of black slavery in North America and the civil rights movement of the 1960s. It's going to take more than 50 years and one black president to heal that history -- and Obama knows it