Senate Minority Leader Harry Reid insisted on Monday that Republican plans to block a Supreme Court successor to the late Justice Antonin Scalia would amount to blocking the entire Judicial Branch.

In his first floor speech since Scalia's death, the Nevada Democrat accused Majority Leader Mitch McConnell of "an unprecedented attempt to hold hostage an entire branch of government" by not taking up President Obama's eventual nominee.

Reid said McConnell should take up President Obama's nominee, who has not yet been chosen, and said the Constitution calls on the president to nominate justices to the Supreme Court.

Not considering the nominee in the Senate, Reid said, "runs contrary to two centuries of precedent."

Republicans, meanwhile, have noted that key Democratic leaders were interested in blocking Republican appointments toward the end of the last two Republican presidencies. Video surfaced on Monday showing then-Sen. Joe Biden calling for Democrats not to hold a hearing on any potential nomination from President George H.W. Bush.

McConnell, R-Ky., has not announced whether he would take up a nominee but said in a statement after Scalia died that the next Supreme Court justice should be chosen by the president who succeeds Obama.

Republicans have pointed to Democratic statements in opposition to confirming a Supreme Court justice during an election year.

"There is not one shred of evidence in the last 116 years to back Republicans' claims," Reid said. "Democrats never stopped a Republican Supreme Court nominee from receiving a hearing and ultimately getting a vote on confirmation. Never."