The president travelled to tornado-wrecked Joplin, Missouri, a day after returning from a European tour of Ireland, Britain, France and Poland.
The president was to visit survivors and family members of the worst tornado in decades, a monster storm that tore through Joplin a week ago leaving more than 130 dead and hundreds more injured. More than 40 people remain unaccounted for, and the damage is massive.
The president was set to tour destroyed neighbourhoods in the city of 50,000 in southwestern Missouri, and speak at a memorial service being held by local clergy and governor Jay Nixon for those who lost their lives. He was set to offer federal assistance, and his own condolences.
However, the president's task as healer was set against an unfriendly political background. Mr Obama narrowly lost Missouri to Republican Senator John McCain in 2008, but in Jasper County, where Joplin is located, McCain won by a large margin: 66 per cent to 33 per cent.