The White House says President George Bush will try again to get Senate approval for 20 people he has nominated to become federal judges.
Some of Mr Bush's nominees have strong anti-abortion views
Democrats in the Senate blocked some of them during Mr Bush's first term saying they were too conservative.
A White House spokesman called them highly qualified.
Correspondents say Mr Bush's move may herald fierce battles over the judiciary in Mr Bush's second term as president, which starts in January.
A number of the vacancies are in the second most important courts in the US, the Courts of Appeal.
Mr Bush has struggled to get his nominations through the Senate because up to now the Republicans have had only 51 seats out of 100.
Backlog of cases
This has enabled Democrats to filibuster, and prevent the nominations being put to a vote, which requires the consent of 60 senators.
However, the Republicans will now have a majority of 55, putting the 60-vote target within easier reach.
"The president nominated highly qualified individuals to
the federal courts during his first term, but the Senate failed to vote on many nominations," said White House spokesman Scott McClellan.
The delay "only exacerbates the issue of judicial
vacancies, compounds the backlog of cases, and delays timely justice for the American people," he said. He added that the Senate has a constitutional obligation to vote on the judicial nominees.
But Senator Harry Reid of Nevada, the Senate's new
Democratic leader, disagreed.
"It's a disservice to the American people to detract from
the important work of the Senate to reconsider these failed nominees," he said, according to Reuters news agency.
Some Democrats have also charged that the move undermines Mr Bush's post-election promise to reach out to opponents.
Several of the appeals courts nominees are controversial.
They include Priscilla Owen, a Texas Supreme Court justice with strong anti-abortion views, and Pentagon general counsel William Haynes, who is thought to have written or overseen memos authorising harsh treatment of detainees at Guantanamo and in Iraq.
Correspondents say political battles are likely not only over the federal judgeships, but over seats in the Supreme Court.
One member of the Supreme Court has been ill with cancer, and other judges are believed to be close to retirement.