Obama unveils centrist Garland as Supreme Court pick

U.S. President Barack Obama chose the centrist judge Merrick Garland for a pivotal vacancy on the Supreme Court March 16, warning Republican foes their "unprecedented" refusal to consider his nominee threatens the integrity of U.S. institutions.

Obama tapped the 63-year-old judge to replace conservative stalwart Justice Antonin Scalia, who died unexpectedly on March 13.

Supreme Court justices are appointed for life and the body's rulings can exert a powerful influence on major social issues in America.

Obama said Garland's experience - from prosecuting the Oklahoma City bomber Timothy McVeigh to serving as a clerk for late Justice William Brennan - "have earned him the respect and admiration of leaders from both sides of the aisle." 

Standing at Obama's side during a ceremony in the Rose Garden, Garland became emotional as he described his humble upbringing in Chicago, and vowed to be faithful to the U.S. constitution if confirmed for "the greatest honor" of a Supreme Court seat.

"Trust that justice will be done in our courts without prejudice or partisanship is what, in a large part, distinguishes this country from others," Garland said.

But Republicans fear Garland will tip the even balance of the court toward liberals and have vowed to refuse him even a Senate confirmation hearing.

Senator John McCain said that Obama's "lame-duck" presidency should leave the appointment to next president, who will take office in January next year.

"I believe the American people must have a voice in the direction of the Supreme Court by electing a new president," he said.

Obama - himself a former constitutional law professor - made an impassioned case for Republicans to reconsider.

"I simply...