Over 4 million people are expected to descend on Washington’s Mall in January to celebrate President Obama’s inauguration, in what will surely be the largest gathering in U.S. history. As Obama said on election night: “Change has come to America.”

It’s simply huge. Like an earthquake, it has shaken the foundations of U.S. politics. Like a tidal wave, it is sweeping away the deadwood and Bushes standing in its way.

A political realignment has occurred. Given the scope of the victory and the economic challenges of the times, the Internet-driven and people-centered mass movement that brought it about must be built on and even broadened further to see it through. A 4-million-strong inauguration party is great way to begin.

With this new president at its head, the movement for unity, hope and change is sure to continue to grow and build upon its independent base.

What worked in the primaries and the general election — grassroots organizing complemented and organized by the power of the Internet and social networks — will have even greater force now as organizing efforts begin to achieve a people’s legislative agenda. Setting a timetable for Iraq troop withdrawal, achieving national health care, passing the Employee Free Choice Act, providing homeowners in danger of foreclosure with assistance along with addressing the economic crisis — these will require a political campaign unmatched in recent memory.

Fully aware of what’s at stake, Obama has already, in one of his first acts, taken his message directly to the people in a YouTube video. The U.S. has arrived at its first “interactive presidency,” with the new president using the vehicle of on-line organizing to achieve legislative goals and to involve the broad masses of the people in the act of governing. With the coming together of politics, ideology, culture, communications, video and audio within a single interactive platform, the decision-making process itself is changing. Politics has entered a new stage. Sociability and connectivity are empowering working-class citizen-activists in ways unheard of a few years ago.

By taking it to the people on YouTube and in other ways, a united movement to consolidate the victory and bring real change has begun. See you on the Washington Mall in January!