President Barack Obama on Tuesday rebuked Republican senators for threatening to refuse to consider his nomination of a successor to Supreme Court Justice Antonin Scalia. The president said he had a constitutional duty to select a new justice in the wake of Scalia’s death over the weekend, and that Republican senators also had an obligation to “do their job” to move the process forward. “The Constitution is pretty clear about what is supposed to happen now,” Obama, a former constitutional law professor, said at a press conference at the end of the two-day summit with Southeast Asian leaders. Senate Majority Leader Mitch McConnell has argued the seat should remain empty until a new president takes office next January.