The term pledge is used in three ways:
A promise or commitment to contribute money
A promise or commitment to a policy or principle
The Pledge of Allegiance
It is the Senator’s policy not to sign pledges. She feels that it is her responsibility to make decisions that are in the best interest of the constituents in her district and for the nation as a whole. Even if she supports the principles behind a pledge she will not bind herself to any document that could limit her ability to do her job properly in the future or feel the need to hide behind a pledge because she does not have the courage to stand up for her principles on her own.