"My job, as president, is to advocate for policies that generate more opportunity for everybody -- policies that strengthen the middle class and give more people the chance to climb their way into the middle class," Obama said in a commencement address at historically black Morehouse College in the southern city of Atlanta, Georgia.
"Policies that create more good jobs and alleviate poverty, that educate more children, that give more families the security of health care, and protect more of our children from the horrors of gun violence," he added.
Republicans have been fiercely critical of the White House, saying the trio of scandals -- including one related to alleged abuses by the tax-collecting Internal Revenue Service -- are illustrative of an administration guilty of an egregious abuse of power.
The other controversies are linked to cover-up claims from Republicans in Congress about the deadly September 11, 2012, attack on the US mission in Benghazi, Libya, and the government's secret seizure of phone logs from reporters at the Associated Press.
"Others may get distracted by chasing every fleeting issue that passes by, but the middle class will always be my number one focus, period," he said.