This is a general ambiguous statement a number of people are offering up as a credible argument.
1) Name the people that dissented to Reagan and Bush's picks. Research if there were majority dissents or the majority accepted without question. Did you know g.W.B. dissented on Souter when his father slected him? Research histories of each of these candidates. For example, did you know kennedy defended O'Connor's right to not answer the R v W question? certainly appears he had an inkling of her mindset at the time. Research the history of Roberts. How is it comparable and how is it not comparable to Scalia, rehnquist, Thomas, kennedy, Stevens and O'Connor's histories when they were nominated.
BTW, your initial premise is wrong. At least in 41's case he had an inkling and was warned off by close confidants, and chose to trust the wrong person. It wasn't a matter of lack of knowledge, but poor judgement of character that led to that pick. With Reagan, he sought to name a woman. Right there you have the answer to O'Connor. His goal was not what it should have been when searching for a Justice.
A number of people are demonstrating prejudice against Roberts based on history of prior GOP nominees, but neither Roberts nor G.W.B. carries this questionable history with the Supreme Court or Court in general. If interested in fairness, a person would NOT accuse Bush of being alike Reagan and 41 in matters of the court given his track to date, nor accuse Roberts without fact to be Souter.
How do you know the President is trying to accomplish the same goals with this pick that you are hoping he is trying to accomplish? The best assurance that a judicial pick is "secure" is a past record of faithfully applying the consititution on the bench - a record which Luttig, Alito, and Garza have, and Roberts does not.
Let's toss aside the false argument the Justices you name are exemplary by any conservatives standard. Should they have been chosen, some conservative would have complained. If brown had been selected, some would have been unhappy. A Justice is only ever a consensus conservative pick AFTER years on the Court in which suspicion is broken.
Second, if I recall correctly, prior to the nomination of Roberts a number were recently unhappy with Luttig given a recent decision against the administration in the WOT.
To your question, how do I know what the President is trying to acommplish? He told me. He stated he wanted a Justice that would not make law. A Justice that would not legislate from the bench. A Justice that would interrupt the Constitution.
The President is not a liar. Whether you agree or disagree with him, he tell you what he believes. Where he stands. And he doesn't make a habit of twisting himself into knots to be liked. If after five years you do not recognize this characteristic, I doubt you ever will. But I remind when those tapes by a "friend" that secretly taped him were released, the candidate then Governor Bush was the same man we knew as president Bush. So that is how I know what the president's goals are. He told me, and he is an honest man.
Hear, hear.
Bush takes the path of least resistance with every domestic decision he makes. Roberts was definetly nominated because he would be acceptible to Democrats. I hope he was also nominated because he is a textualist or an originalist. Given Bush's tendency to alienate conservatives, I am not going to get my hopes up.