He does not want to abolish it; just to modify it. Read his reasons;
End the filibuster! An interview with Sen. Tom Harkin
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Health-care reform has, in part, focused a lot of attention on the seemingly dysfunctional process that produced the bill. Your colleague Sen. Jeff Merkley has begun talking about it. Paul Krugman and Andy Stern have focused on it. Bloggers have turned their attention to it. But you've been making some of these arguments since the 90s. Is the situation worse now than it was then?
It's becoming impossible. The situation in the Senate is an offshoot of the old Newt Gingrich philosophy. Back in the 1980s when I was in the House with Gingrich and the Republicans won the presidency and the Senate, Gingrich was asked if the Republicans would ever take the House, too. He said yes, but we'll have to tear it down first. So that's what they did. Took them 10 years, or even more. But it was a constant attack. And now it looks like they're trying to do that in the Senate.
In the past, we've always had one or two or three senators who would try to block something. The most famous was Jesse Helms. He could tie people up in a conniption. But the thing is, when he went too far, his leader, Bob Dole, wouldn't put up with it. Neither would Trent Lott. And later on, even Bill Frist. You allow him to do so much, and after awhile, you say, that's enough.
Now we have more of the Jesse Helms. The Vitters and DeMint and Coburn, and maybe throw in Inhofe and a couple other newcomers, and they now run the minority. You don't have a minority leader putting them in check, saying we have to work together. Dole would never put up with what's going on over there. Neither would Trent Lott. We've had 101 objections from Republicans to proceeding.
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more:
http://voices.washingtonpost.com/ezra-klein/2009/12/end_the_filibuster_an_intervie.html