That is an incredibly irresponsible and destructive vow, but you're welcome to make it and keep it. Just be prepared to accept responsibility for the consequences.
Why is it irresponsible or destructive? In 2004 I will be faced with selecting either A) Someone who will sign unconstitutional laws or B) Someone who DID sign unconstitutional laws. In this lineup of selections, selecting no evil -- no one -- is the only responsible thing to do.
Being realistic does not mean one has abandoned one's principles.
BS. He abandoned his principles. He swore an oath to uphold the Constitution and Bill of Rights but just acted, willfully and with aforeknowledge of the results, against that Constitution and Bill of Rights.