The first one comes from a while back, when the President insisted that he did not need a Warrant to listen in on the telephone conversations of United States Citizens, despite Supreme Court rulings otherwise, the Fourth Amendment, and an unquestionably reasonable alternative to his program (the FISA courts which have a 99.96% Warrant Approval rate and are available post facto). The president's position was that this was a necessary tool in the war against terror and that it's not unconstitutional as he understands the Constitution, and besides, if you have nothing to hide, then why the concern if someone is listening, but they won't be listening anyway, because the NSA follows strict guidelines, but we can't tell you what those are because it would help the Enemy (you know, Terror, which is not an entity, but a theory and therefore the War on Terror could conceivably never end). i can't begin to tell you how many people (all Bush apologists) who argued that this is a minor inconvenience - yes, facially violating the Fourth Amendment is a "minor inconvenience" - and I need to be "rational."
Now, these same people are defending Alberto Gonzalez and the administration in defending him against requests to go up before Congress pursuant to a subpoena to testify as to the involvement regarding the firing of 8 US Attorneys for, what the document dumps have illustrated, appear to be partisan reasons (i.e. they weren't "loyal bushies"). The president has gone so far as to say that he has proposed "reasonable" alternatives to testifying under oath, which is, talking off the record, and that the information Gonzalez et al. possess is protected under "executive privilege." This is a separation of powers issue, and there is certainly an issue to consider as to whether or not this is something that could be protected by executive privilege. I would like to limit executive privilege, and I fear that the administration's attempts to expand it would impermissibly extend the power of the executive branch to such point that there may no longer be co-equal branches in government, which is, in my estimation, exactly what this president wants - expansion of Presidential powers under a Unitary Executive Theory. For those Republicans who support this concept, I ask you, are these the keys you'd be willing to hand Hillary should she win in '08? That scares me almost as much as Bush operating under this theory, but I digress. The point is that in this case, the President has essentially been asked - "if you have nothing to hide, then why do you resist these people going under oath to testify?" One idea, as John Dean, the author of the link above says: "[Y]ou show me a White House aide who does not want his conversations and advice to the president revealed, and I will show you someone who should not be talking with or advising the president."
Anyway, here's the contrast - the first problem is a Constitutional issue - the administration violated the Fourth Amendment - the rights preserved for the protection of the People from the overreaching of the Government. The second one is a personal issue. Nowhere in the Constitution or the Bill of Rights is there any mention of "executive privilege." The concept, such as it exists, is a creature of the Administrations past (Nixon and Clinton relied on this concept), and any reach it does have is limited and should remain limited - lest we become a nation of subjects and no longer a nation of the Free.