That's true, to an extent. However, you are able to verify to a degree by examining rulings on lower courts and looking for conservative judicial opinions.
Alito had those - Miers did not.
You may be right - Miers might have been great.
But in a situation where you don't get a do-over (see Souter, David), you simply cannot take that chance.
Nobody knew her better than the President, and I trusted his judgement.
If she had come up short in the hearings, fine. But trashing her because the far right didn't trust the President was a very, very bad move.
The Mistake of the Miers Withdrawal
11-01-05
Harriet Miers has now withdrawn her nomination and Samuel Alito has been nominated in her stead. Although Judge Alito is an excellent conservative choice, and the style of nominee that the conservative right clamored for, not allowing Miers a hearing before the Senate Judiciary Committee was a mistake.
In "borking" Miers, the conservative movement has shot itself in the foot. No longer do the claims of giving a nominee a hearing on their merits carry any weight. It is now evident that conservative or liberal, Supreme Court nominations are purely an ideological and political event.
The scrutiny given to Miers, in order for the conservatives to prove that she was not conservative enough, looked for all the world the same as a liberal witch hunt. Obscure documents, decades old speeches, business related donations were all used to trash her. George Bush was ridiculed and insulted daily on the most conservative web logs, in order to prove to others that he could not be trusted to nominate a conservative. Comments that Miers would be a good secretary or should be limited to getting coffee were as sexist as I have seen in recent memory. George Bush was called a liberal, a traitor to conservatives, ignorant, etc. Ann Coulter had maybe the worst cheap shot of all claiming George Bush had gone back to drinking. Even Laura Bush was trashed, accused of making the pick for the President and then claiming that sexism could be part of the negative response to the pick ( a passing comment made in answer to a question from an interviewer).
As a strong supporter of the President, I was appalled at this response from a group of people that should know better than to use the same arguments that they defended this President from when the comments came from the left. The effect is that now the public knows that there is no difference politically in the left and the right.
The damage is not only to the image of the President but also the conservative movement in general. Whether far right conservatives like it or not, George Bush is the face of conservatism in the country, and he is reviled daily for the conservative stands he takes. When he is referred to as a liberal by other conservatives, the non political public can easily see that those conservatives are off the reservation. When the far right of the conservative movement can dictate an already conservative President’s Supreme Court nomination, it sends a chilling message to moderates. The moderate swing vote determines who is elected in this nation, and a fight like we have seen over Harriet Miers will alienate them.
Another cost is that the brutal and often unfounded criticism of the President not being limited to his liberal opponents allows these unsubstantiated charges to be leveled at the President in every forum. The rhetoric used on the conservative side against the President and Harriet Miers will be used as a weapon against Republicans in the next election. Statements by leading conservative pundits and politicians will be parroted by the left, and there is no response available that will not paint these conservatives as hypocrites.
The Harriet Miers nomination was, at the heart of the matter, a debate on the trust our President deserves. Not understanding the reasons behind the nomination of Miers, the consensus from the right was that he could not be trusted. That destroys the footing that has given the Republican Party gains in all areas for the last three election cycles. The Republican Party and conservatives in general have made a terrible mistake, and we will pay for it in the next election.