One quote isn't all that exceptional -- that is the one allowing restriction of speech prohibiting speech that might cause or incite harm. All that seems to be doing is saying that one can't cry "fire!" in a crowded movie theater.
The other, suggesting that government might have the right to "unskew" debate by legislative redistribution of speech, is appalling. But as I've been arguing in other contexts, that's the mainstream left-of-center view of free speech -- it's one of the premises underlying McCain Feingold, and the rationale has been floating around for years in liberal circles.
Remember the old joke about how it's not what's illegal in Washington that's the problem -- it's what's legal? Analogously, here, what's scary isn't just what Elena Kagan may or may not think. . . the truly scary thing is that most of those things are mainstream in liberal-land.
I believe that the "solution" to what I might deem wrongheaded speech is more speech. Let the marketplace of ideas flourish. But then, as a conservative, I believe in the free market. Many of those on the left . . . not so much.