... because it empowers Congress to give us "some of the best things that government has done for the better part of a century, and some of the best things that lie ahead."
That's the argument. The Constitution should mean what it needs to mean so that we can get the things that we want from government — all those fine things that government deigns to do for us. The NYT tells us that some conservatives are "infuriated" because Kagan "refused to take the Republican bait and agree to suggest limits on that clause’s meaning." They're angry because they don't like the good things government does. Those bad old obstructionists. They're the Party of No.
The idea that constitutional law stands apart from political preferences is nowhere to be found. I guess NYT readers aren't supposed to notice that.