If you look up to Lori Lipman Brown and Sean Faircloth, the Secular Coalition for America is looking for their next Executive Director and you could be following in their footsteps:
The Executive Director will be the primary public face for the organization, be a central force in leading the organization, and cultivate relationships with current and prospective donors, member organizations, the media, and legislators. Additionally, the Executive Director must play an active role in nurturing the relationships between the member organizations, promoting cooperation and advancing the nontheistic movement as a whole. The Executive Director will work with and report directly to the Executive Oversight Committee of the Board of Directors, and set goals and priorities for other staff members based on the strategic plan of the organization.
All the details are here. You’d obviously have to live in (or move to) Washington, D.C., but if you want a job in the movement, this is definitely one of the more higher-profile ones.