Senator Charles Grassley (R-Iowa) at a Senate Judiciary Committee hearing on Capitol Hill in Washington, July 14, 2009. REUTERS/Joshua Roberts

The U.S. Court of Appeals for the D.C. Circuit’s stunning decision this week to strike down a National Labor Relations Board rule requiring employers to post signs reminding workers of their right to organize, is a clear indication of why this D.C. court has become an ideological battleground.

Senate Republicans, in particular, are going to great lengths to preserve their partisan advantage on a court widely regarded as second to the Supreme Court in importance.

First, Republicans manufactured a controversy over Caitlin Halligan, President Barack Obama’s well-qualified nominee to the D.C. Circuit, and then torpedoed her confirmation through a partisan filibuster.

Then the Republican members of the Senate Judiciary Committee, led by its ranking member, Chuck Grassley (R-Iowa), took a startling step: They introduced legislation that would eliminate three of the 11 judicial seats on the D.C. Circuit, claiming the court’s caseload does not justify those seats. Grassley is proposing to cut almost 30 percent of the D.C. Circuit’s seats without any study showing that such a gutting of the court is warranted.