It was last summer when former President Barack Obama delivered the eulogy for the late Rep. John Lewis (D-Ga.) and made some news in the process. Reflecting on possible voting-rights legislation, and the inevitability of a Republican filibuster, Obama called the legislative tactic a “Jim Crow relic,” while arguing that it may be necessary to eliminate the filibuster “in order to secure the God-given rights of every American.”

The former president’s Jim Crow reference served as a reminder that the Senate tactic has been used by some notorious figures to stand in the way of civil rights. It also helped steer the argument for reform advocates: in the effort to alter the filibuster rules, proponents have been increasingly vocal of late emphasizing the ugly ways in which the tactic has been used in history.

Sen. Elizabeth Warren (D-Mass.), for example, noted last week that the legislative filibuster “has deep roots in racism.”

The line of argument, evidently, has bothered Congress’ top Republican. NBC News reported last night:

As Republicans work to preserve the Senate’s 60-vote threshold for most legislation, Minority Leader Mitch McConnell made the case Tuesday that the rule should be measured by its origins, not the instances it was used to perpetuate racism. McConnell argued in a speech early Tuesday on the Senate floor that Democrats are exploiting race in their attempts to overhaul, or outright abolish, the filibuster.

A Washington Post report quoted the Kentucky Republican telling reporters, in reference to the filibuster, “It has no racial history at all. None. There’s no dispute among historians about that.”

That wasn’t even close to being true. The filibuster has been used many times in contexts unrelated to race, but to argue that the tactic “has no racial history at all” is plainly at odds with the historical record.

Vox’s Ian Millhiser explained last year that the Senate filibuster is “a historical accident that became a tool of white supremacy.”

If Republicans were to use the filibuster to stop legislation expanding voting rights, they would join a long and inglorious tradition of illiberal senators filibustering civil rights legislation. From 1875 until 1957, Congress did not enact a single civil rights bill, even as Jim Crow flourished in the South. Congress could not even pass civil rights legislation that enjoyed majority support. Between the end of World War II and 1957, when a modest bill finally became law, the House passed five civil rights bills. But white supremacist senators were able to block each of these five bills using the filibuster.

Political science professor Sarah Binder wrote a related analysis yesterday, explaining “Historians know that the filibuster is closely intertwined with the nation’s racial past and present. To be sure, senators have filibustered issues other than civil rights over the Senate’s history. But it is impossible to write that history without recognizing the centrality of race.” She added:

To study filibusters after the Senate created cloture in 1917, [political scientist Steven Smith] and I counted up measures “killed” by a filibuster. We sought evidence that a majority of the House, a majority of the Senate, and the president favored a measure — and yet it still died after debate on the Senate floor. In doing so, we found that, of measures derailed by filibusters in the 20th century, civil rights measures dominated. Of the 30 measures we identified between 1917 and 1994, exactly half addressed civil rights — including measures to authorize federal investigation and prosecution of lynching, to ban the imposition of poll taxes, and to prohibit discrimination on the basis of race in housing sales and rentals.

From debates over civil rights to statehood, voting rights to lynching, the Senate’s filibuster rule has been used to advance the cause of racial injustice.

McConnell’s office clarified yesterday afternoon that when the Republican leader said the filibuster “has no racial history at all,” he was referring to its historical origins, not its uses.

It was an important explanation, though McConnell ended up doing the opposite of what he intended: he reminded us that those eager to emphasize the filibuster’s ugly past have a point.