Dozens of seats on the federal bench remain empty, and Washington can't agree on who's at fault.

"The blame lies with the Republican Party," Nan Aron, president of the Alliance for Justice, puts it simply. She's convinced that GOP senators are stone-walling qualified nominees in hopes that a Republican will re-take the White House and be the one to fill the seats.

Sen. Mike Lee, R-Utah, who sits on the Judiciary Committee, says the numbers tell a different story: There are 77 vacancies but only 31 nominees currently pending.

"This really isn't about the Senate," Lee said. "This is about the fact that the president isn't making these nominations."

Aron argues that there are likely other potential nominees in the mix who can't get past an initial roadblock. When the White House wants to nominate an individual, the name is presented to the senators from that potential nominee's home state. Until the senators submit what's known as a "blue slip" for that person, the nomination cannot proceed.

"In so many states around the country, Republican senators are withholding their blue slips," Aron says. However, the blue slip process is conducted largely out of public view, and details are nearly impossible to confirm.

When asked about all the empty seats on the bench today, White House Press Secretary Jay Carney responded, "One thing we know for sure is that the pace of confirmations has never been slower."

But according to newly released numbers from the Alliance for Justice, Obama's nominees are being confirmed at rates nearly identical to those Presidents Bill Clinton and George W. Bush faced. Up to this point in their terms, both Clinton and Bush had 78 percent confirmation rates. Today, Obama's stands at 77 percent.  

Lee says the hard data proves his point about the president's failure to nominate more candidates.

"They are being confirmed, but it's just that the president hasn't nominated most of these slots," he said.