The politics surrounding President Bush’s surveillance bill have split the membership of a traditionally neutral think tank, the Foundation for the Defense of Democracies.

The head of the foundation, Clifford May, confirmed for Newsweek that several prominent Democrats had resigned after an affiliated group began running political ads targeting 15 Democratic members of Congress. Those quitting the foundation include Sen. Chuck Schumer, Rep. Eliot Engel and Democratic strategist Donna Brazile.

May, former communications director for the Republican National Committee, also heads the new organization, which has a similar name - Defense of Democracies - but a sharper political focus.