President Obama punched back Tuesday at Republicans who have threatened to delay the nomination of a successor to the late Justice Antonin Scalia until there is a new president.

“The Constitution is pretty clear about what is supposed to happen now,” the president wryly noted. “There’s no unwritten law that says that it can only be done on off-years.”

His remarks came at a press conference at the U.S.-ASEAN summit in California.

“When there is vacancy on the Supreme Court, the president of the United States is to nominate someone, the Senate is to consider that nomination, and either they disapprove of that nominee or that nominee is elevated to the Supreme Court,” Obama said. “Historically, this has not been viewed as a question.”

In the hours after Scalia’s death was reported, Senate Majority Leader Mitch McConnell and other Republicans insisted the new justice shouldn’t be chosen by Obama because there is a presidential election in November.

“I’m amused when I hear people who claim to be strict interpreters of the constitution suddenly reading into it, a whole series of provisions that are not there,” Obama said. “There is more than enough time for the Senate to consider in a thoughtful way, the record of a nominee that I present and to make a decision.”

The President pushed back on the idea that he might chose a moderate, saying only that the nominee would be “well-qualified” and able to serve with honor and integrity. He also said the Senate Republicans’ current vow to obstruct the nominee is part of a pattern of blocking judicial nominees for lower courts and executive branch positions. When asked by a reporter about his own support of a filibuster of Justice Samuel Alito, then a nominee of President George W. Bush, Obama shot back that “Justice Alito is on the bench right now.” He also brought up the Senate confirmation of Justice Anthony Kennedy in the last year of President Reagan’s term.

“The fact that it’s that hard, that we’re even discussing this, is, I think, a measure of how, unfortunately, the venom and rancor in Washington has prevented us from getting basic work done,” Obama said. “Now, this would be a good moment for us to rise above that.”