The Senate tactic known as a filibuster has been much in the news lately. Democrats used the filibuster to stall votes on the nominations of federal appeals court judges and John R. Bolton as ambassador to the United Nations but usually employed the less bellicose term extended debate. (In Bolton’s case, Bill Frist, the Republican majority leader, disagreed, saying it “looks like a filibuster, sounds like a filibuster [and] quacks like a filibuster,” and even Harry Reid, the Democratic minority leader, had to agree.) Republicans, meanwhile, backed away from the term “nuclear option,” the radioactive name for their plan to bypass the Senate rule that requires 60 votes to end a filibuster. Instead they began calling it “the constitutional option.”

The relevant Senate rule, No. 22, is itself the product of a filibuster. In early 1917, when President Woodrow Wilson asked for authority to arm merchant ships in order to deter German U-boat attacks, the House approved overwhelmingly (403–14), but 11 senators (“a little group of willful men,” in Wilson’s words) took advantage of the traditional right of unlimited debate in the Senate to filibuster the bill to death. That spring the newly elected Senate adopted Rule 22, providing that debate could be cut off by a two-thirds vote (amended to three-fifths in 1975).

Filibusters—or, more often today, the mere threat of one—have been used to delay, kill, and amend legislation since 1790, but they were rare until the 1840s, and the name for the tactic dates only from the 1850s. It crops up first in the written record as a verb, with the earliest example in The Oxford English Dictionary coming from the Congressional Globe of January 4, 1853: “I saw my friend … filibustering, as I thought, against the United States.”

The source of the word is the Dutch vrijbuiter, meaning a “freebooter,” or pirate. This was adopted in the eighteenth century in French and English as filibustier and in Spanish as filibustero . It was applied to William Walker and other adventurers who attempted after the Mexican War of 1846–48 to take over parts of Mexico as well as nations in Central America and the West Indies that had recently gained their independence from Spain. To Spanish speakers, these land pirates looked much like seagoing filibusteros , and the word was reacquired in English from its Spanish form. So to those originally using the term, practitioners of a filibuster were akin to unwelcome invaders. Supporters, by contrast, saw themselves as more like freedom fighters. The dispute continues today, with sides changing along with each change in control of the Senate.

—Hugh Rawson