WASHINGTON -- U.S. President Barack Obama is reprising his role as chief comforter as he returns once again to a grief-stricken corner of America to mourn with the families of those killed last week at Fort Hood and offer solace to the nation.

It's a duty that Obama has had to fulfil far too often.

Tucson. Aurora. Newtown. Boston. Washington Navy Yard. Fort Hood -- twice.

The names of these communities have all become synonymous with tragedy in the years since Obama took office, each challenging the president to find ways to impart meaning to senseless death.

"Increasingly, giving these eulogies has become a central responsibility for our presidents," said Michael Waldman, who helped write many eulogies as President Bill Clinton's chief speechwriter. "A president is not just a political leader. He is the head of state and speaks for the whole country."

But as Obama returns to Fort Hood, Texas, on Wednesday, he brings little in the way of solutions to offer a society that has been confounded by the frequency of events that have jolted Americans out of their sense of security. For a president who is on the path to ending two wars, warding off violence at home has proved an elusive challenge.

The last time Obama came to Fort Hood, in the wake of another mass shooting in 2009, he told residents of the central Texas community that the 13 lives they lost would endure, their legacies safeguarded by the nation whose protection they had made their life's work.

Like an improbable bolt of lightning, tragedy has struck twice at Fort Hood. Army investigators are still piecing together what led to Spc. Ivan Lopez's deadly, eight-minute rampage last week, on the same sprawling post where an Army psychiatrist unloaded on his comrades five years earlier.

In the days after a 20-year-old gunned down elementary school students in Newtown, Connecticut, Obama said he had been reflecting on whether America was doing enough to prevent such violence. He concluded that it was not.

"We can't tolerate this anymore. These tragedies must end. And to end them, we must change," Obama said as he consoled heartbroken parents at a prayer vigil.

There are few signs today that a new push to address such societal ills through public policy is in the works.

Obama's efforts to seek stronger gun control protections fell flat in Congress. What some hoped could be a productive national conversation about mental health raised fears that patients could be stigmatized by the actions of criminals.

In the face of such long odds, the president may be reluctant to generate undue hope that the nation will enact new laws or programs. White House spokesman Jay Carney said Obama's speech Wednesday will focus on the victims and their families, not on policy.

Adding complexity to the president's response are questions about whether the suspect's wartime service precipitated his actions. Although Lopez did a short stint in Iraq in 2011 and said he suffered a traumatic brain injury, Fort Hood officials have said his mental condition was not a "direct participating factor" in the shooting.

Such is the fraught political terrain that Obama's speechwriters must traverse as the president prepares, once again, to console a nation in grief.