Every one of those arguments translates into "trust me". What evidence does Newt have that she will "strictly apply the laws of the constitution"? We've heard that a thousand times before, it's easy to say it, it's harder to demonstrate it. "Trust me" isnt' enough.
Not this one:
she proved to be a very effective leader opposing the American Bar Association's official stance in support of abortion, including active support of taxpayer-funded abortions
This is something Harriet Miers actually did BEFORE she was in the WH to demonstrate a prolife position.
What evidence do we have they any nominee will act in a particular way once they have been appointed? None, none whatsoever. Once on the Supreme court they answer to no one and can do as they please.
The best guarantee you can have that this will not happen is if you have personally know the candidate for a long period of time. President Bush knows Harriet Miers much better than any other candidate, hence the reason for picking her.