Can our nation afford political waffling on issues of scientific consensus? Stan Honda/AFP/Getty Images hide caption

itoggle caption Stan Honda/AFP/Getty Images

Grover Norquist, founder of Americans for Tax Reform and the man behind the pledge. Jim Watson /AFP/Getty Images hide caption

itoggle caption Jim Watson /AFP/Getty Images

Americans for Tax Reform President Grover Norquist speaks on Capitol Hill in April. Lauren Victoria Burke/AP hide caption

itoggle caption Lauren Victoria Burke/AP