The establishment of the Senate was one such check, and it is in the very nature of that institution that the possibilities for obstructionism arise. To begin with, the Senate was conceived as the chamber where the smaller states would be placed on an equal footing with the large; each state, regardless of population, was to have two senators. As a result the balance of power is tipped directly to the minority. In the current Senate, for example, twenty-six states representing a mere 17 per cent of the population have a total of fifty-two senators; twenty-four states representing 83 per cent of the population have forty-eight.

Moreover, because of its smaller size the Senate is a more intimate and less formal chamber than the sprawling House of Representatives. As a consequence its rules are far more flexible, and it is possible to conduct business in deference to the wishes of a single member. In contrast to the House, where bills are generally introduced and acted on one by one, the Senate may have before it as many as five separate measures at any one time, moving back and forth among them as the membership desires.

What governs in the Senate are two key elements, the first of which is the rule of comity, or senatorial courtesy. Any member is free to request unanimous consent to almost any act, including a violation of the rules, with the virtual certainty that his request will be honored. The objection of a single senator to an executive appointment in his home state, for example, is customarily sufficient to doom the appointment.

Second, the Senate from the first has permitted unlimited debate on any measure. It is a hallowed right, and in a chamber where the fine points of custom are more respected than the points of parliamentary rule (though the two are often inseparable), any effort to interfere with a member’s desire to speak is viewed with deep suspicion. There is a “germaneness” rule requiring that for three hours each day all senators must speak to the point in debate, and no senator may speak more than twice in a legislative day (which may through recess continue for several calendar weeks); but both of these rules are weakly enforced at best and more often than not are dispensed with entirely on a motion of mutual consent. There are, in fact, only two ways in which debate in the Senate can be involuntarily closed: by unanimous consent agreements —which fail if a single member objects—and by a cloture petition approved by sixty senators, a figure devilishly difficult to achieve in normal circumstances.

The House of Representatives, by contrast, is not a chamber of debate like the Senate. Since the last half of the nineteenth century, when its swollen membership forced the change, the House has done 90 per cent of its business in committee. Again because of its size, the House ordinarily relies heavily on the leadership for direction and follows a strict agenda in its transactions, usually considering only one bill at a time on the floor. More than a day of debate on any bill is rare because House rules limit formal speeches from all parties to a maximum of two hours. Strict rules also limit the opportunity for filibustering in other ways, so most obstructionism occurs behind the scenes, in committee rather than on the House floor.

Since about 1880 the filibuster has been the mark of senatorial proceedings, and it effectively stops the business of lawmaking in Congress as a whole because the Senate must consent to House legislation—and vice versa—before any bill can become a law.

No one knows for certain how many filibusters have been conducted in Congress, although the number undoubtedly runs into the high hundreds. Any effort to count is frustrated by several difficulties. The debates in the Senate, for example, were kept secret until 1794; thereafter they, like the proceedings in the House, were only scantily reported by the several commercial printers who regularly offered compilations of congressional business between 1789 and 1873. Only with the appearance of the official Congressional Record in 1874 did full verbatim accounts of the debates in both houses become available, and even here the reporting is not always reliable, because many of the printed speeches have been edited for publication after delivery, and some have never been delivered at all.

More important, there is often a fine line between a skillful use of parliamentary rules with the intent to persuade wavering members to shift their votes on crucial issues and the parliamentary maneuvering that is simply a tactic to delay. The length of time expended on such moves is by itself no indication that a filibuster is in progress; some of the most effective filibustering may take place in a matter of a few hours if a measure is introduced on, say, the last day of a session when the House or Senate is approaching adjournment.

Finally, few members of Congress are ready to announce that they intend to engage in filibustering unless the support they can draw from other members is readily visible and there is some certainty that the tactic will be welcomed by the members’ constituents.

Despite the lore that surrounds the maneuver, few filibusters are exciting displays of rhetorical pyrotechnics or colorful encounters designed to dazzle the congressional membership and the press who witness them. The intent, after all, is to secure delay and to wear the opposition down. As a result most filibustering is quite prosaic, marked by a heavy reliance on obscure parliamentary points, and, in the end, stultifyingly dull. There have been exceptions, however; here are some examples.