All these things -- health care security, American manufacturing, rebuilding America and putting construction workers back to work, making sure our kids are getting a great education and can afford college -- all these things that make up a middle-class life, they all tie together.

WHITEHOUSE: The White House

Perhaps most importantly, the middle class has influenced the aims and make-up of the party itself.

ECONOMIST: The other Moore's law | The

The Senate has already passed a bill that would make sure that middle-class taxes do not go up next year by a single dime.

WHITEHOUSE: President Obama Speaks on the Importance of Extending Tax Cuts for Middle-Class Families | The White House