“I regret deeply that the Senate has not done its job and they have not permitted a vote on” Merrick Garland’s Supreme Court nomination, Hillary Clinton charged during Sunday’s debate in St. Louis against Donald Trump. Not holding a vote to ensure “the full compliment of nine Supreme Court justices” is a “dereliction of duty,” she said.

Soon after, Judicial Crisis Network Chief Counsel Carrie Severino—a former law clerk to Justice Clarence Thomas—tweeted, “If ‘not permitting a vote’ on Garland is a dereliction of duty, Hillary is equally guilty as she tried to prevent a vote on Alito.”

Severino is correct. When President George W. Bush nominated Samuel Alito to fill the Supreme Court seat being vacated by Justice Sandra Day O’Connor, Democratic senators—including Barack Obama and Hillary Clinton—attempted to filibuster Alito. Even though he had majority support in the Senate Judiciary Committee and among the full Senate, Clinton attempted to stop his nomination from ever coming to a vote.

Clinton failed. In the end, 72 senators voted to end debate, and then Alito was confirmed on Jan. 31, 2006, as the 110th justice of the Supreme Court by a vote of 58-42. But Clinton did everything possible to prevent the Senate from holding that vote.

There is historical precedent for not confirming a Supreme Court nomination made during a presidential election year. There is also an argument that since the American people gave the presidency to one party but the Senate to the other, the voters could debate for several months what kind of justice they want to fill the seat of the late Justice Antonin Scalia.

Indeed, in the past Vice President Joseph Biden has declared the Senate should not vote during a presidential election year. Sen. Charles Schumer says the Senate can wait even longer to prevent Republican nominees—at least 18 months.

There is no such explanation for why Clinton attempted to block a vote on a nomination made only one year into a presidential term. It is unclear whether she might have believed it acceptable to keep open that seat all the way until the end of Bush’s term on Jan. 20, 2009.

But will any reporter in Clinton’s press pool ask her for an explanation?

Ken Klukowski is senior legal editor for Breitbart News. Follow him on Twitter @kenklukowski.