You hear this a lot, and it's always worth reminding people that it's not true. Social Security privatization wasn't doomed by the filibuster. It was doomed because it didn't have a majority of senators on its side. The bill never made it to the floor for a vote (which is where it would have been filibustered). In fact, it never got out of committee at all. There was never even a real bill to speak of. George W. Bush proposed the idea, and it proved so violently unpopular that Republicans decided against pursuing it. Democrats won that one without resorting to minority obstructionism, which is how it should be.That's Ezra Klein, responding to a commenter who supports the filibuster because it can prevent (from his or her point of view) the worst excesses of the other side.
Just on the empirical point about the Bush Social Security plan, I'm not convinced that Ezra is correct. He's right that the bill didn't get out of committee...but that doesn't mean that a majority didn't support it. After all, it's very possible that at least the weaker versions of the public option might have 50 votes in the Senate right now, but the public option never reached a Senate vote because it didn't have 60 votes, and given a 60 vote Senate the majority chose not to put it up for a vote only to lose. I don't know whether that's correct or not about Bush's Social Security plan -- one would need further details about the history -- but I think it's very likely that Bill Clinton's health care plan in 1994 would have progressed a lot farther through the legislative process, and possibly even passed, had there been no filibuster. After Clinton's stimulus failed in the Senate, and after Members of the House voted for the BTU tax only to have the Senate yank it, the House was unwilling to move ahead on health care in 1994 unless they were sure that the Senate was moving too -- and the Senate knew that 60 votes wasn't going to happen, so the whole thing died before passing through even the committee stage.
As for the Republicans under Bush, there were presumably any number of things they didn't even bother trying because they knew they could never get 60 votes in the Senate, and because they wanted the bill, not the issue -- just as the Democrats haven't bothered to try moving labor legislation through Congress this year.