Why do we need legislatures?

Read Antonin Scalia's speech about Constitutional misuse by judges. It's all readworthy, but these excerpts are my target for now:

I am one of a small number of judges, small number of anybody: judges, professors, lawyers; who are known as originalists. Our manner of interpreting the Constitution is to begin with the text, and to give that text the meaning that it bore when it was adopted by the people. ... I do believe however, that you give the text the meaning it had when it was adopted. ...

Although it is a minority view now, the reality is that not very long ago, originalism was orthodoxy. Everybody, at least purported to be an originalists. If you go back and read the commentaries on the Constitution by Joseph Story, he didn’t think the Constitution evolved or changed. He said it means and will always mean what it meant when it was adopted. ...

[He spends some time exposing the fallacies of interpreting the Constitution as a "living" document, then -]

If you believe however, that the Constitution is not a legal text, like the texts involved when judges reconcile or decide which of two statutes prevail, if you think the Constitution is some exhortation to give effect to the most fundamental values of the society as those values change from year to year. If you think that it is meant to reflect, as some of the Supreme Court cases say, particularly those involving the Eighth Amendment, if you think it is simply meant to reflect the evolving standards of decency that mark the progress of a maturing society, if that is what you think it is, then why in the world would you have it interpreted by nine lawyers? What do I know about the evolving standards of decency of American society? I’m afraid to ask.

If that is what you think the Constitution is, the Marbury v. Madison is wrong. It shouldn’t be up to the judges, it should be up to the legislature. We should have a system like the English. Whatever the legislature thinks is constitutional is constitutional. They know the evolving standards of American society, I don’t. So in principle, it’s incompatible with the legal regime that America has established.

I addressed this topic in my post, "Alice in Wonderland" judges - also with quotes from Scalia. Alice in Wonderland is, of course, a much more mature work than generally given credit, rather than the simple children's story it's now recalled to be. As I put it then,

Treating the various [state or federal] constitutions as living documents rather than directive documents brings our legal system into its own Alice in Wonderland, where power, not justice, is the point:

'When I use a word,' Humpty Dumpty said in rather a scornful tone, 'it means just what I choose it to mean--neither more or less.'

'The question is,' said Alice, 'whether you can make words mean different things.'

'The question is,' said Humpty Dumpty, 'which is to be master--that's all.'

If, as Scalia says is happening, judges can simply decide the Constitution means whatever they want it to mean, and overturn legislative acts or mandate new acts (as happened last year in Massachussetts), then why do we need legislatures at all? Lety us go all the way and submit ourselves to the fiat-rule of judges and be done with it.

See also commentary by James Joyner.