Summary: <p>You don't need a majority to gum up the US Senate. With 41 votes, you can call in a filibuster. Republicans defend the filibuster, but Democrats hate it. That's why Democratic senators want to loosen the filibuster's hold around the senatorial throat.</p><p><a href="http://www.princeton.edu/~jzelizer/">Julian Zelizer</a> is a political commentator and a history professor at Princeton University. His books include "Arsenal of Democracy" and "Jimmy Carter." Zelizer sits down with Ross to tell us how a few senators want to bust the filibuster.</p><p></p>
