Democrats should demand a written letter from this government guaranteeing that their privacy was not compromised.

In light of the recent revelations concerning the Bush administration having have spied on US citizens I would suggest that the concern is not whether this government spied on suspected terrorists but that, once it stepped outside the constraints of the law, and the correct legal safeguards were no longer in effect, did they spy on anyone else? Their political opponents, for example.
Once a government has been caught breaking the law it no longer enjoys the "benefit of the doubt" and has created a new, much lower, threshold of integrity for themselves.
Their argued reason for breaking the law is irrelevant. We all want to catch terrorists and we want to catch them quickly, and the current legal requirements allow for that.

I would humbly recommend that all the Democratic candidates from the last general election (2004) demand a written letter from this government guaranteeing that their privacy was in no way compromised as happened under the Nixon administration.