President Obama Monday presented an inauguration address that was hopeful, stressed unity and sought some common ground, yet was unapologetic in defending the societal advances deriving from liberalism.

The president repeatedly returned to the phrase, "we, the people" and sought to stress unified beliefs.

"We believe America's prosperity must rest upon the shoulders of a rising middle class," presenting an argument few would disagree with, but sidestepping the vast political differences about how best to reinvigorate that middle class after years of decline.

President Obama suggested both liberal and conservative thought can lay claim to portions of American exceptionalism. He pointed to a history of government action to provide the "railroads and highways" the "schools and colleges" required of a modern economy; to enact the rules and regulations necessary to ensure fair competition in a free market; and to assure care for the most vulnerable.

Yet in the next sentence he contended Americans, while willing to change and adapt, "never relinquished our skepticism of central authority" or "the fiction that all society's ills can be cured through government." We are a people, said President Obama, who collectively celebrates individual initiative, hard work and personal responsibility.

In policy terms that common ground between right and left might be found in the president's statement that "we must … revamp our tax code" and "make the hard choices to reduce the cost of health care and size of our deficit." President Obama said today's leaders must look to the past and not allow ideological differences to block the nation's advancement.

The president made clear the progressive prioities he will bring to that policy debate - gay rights, removing barriers to voting, immigration reform, and equal pay for women for equal work - continuing the journey toward "the most evident of truths - that all of us are created equal."

"Progress does not compel us to settle centuries-long debates about the role of government for all time - but it does require us to act in our time."

Even on Inauguration Day no one was under any illusion that agreeing how to act will be easy, but the president is right that it is necessary.