President Barack Obama said again on Tuesday that he plans to nominate an "indisputably" qualified successor with an "outstanding legal mind" to replace Supreme Court Justice Antonin Scalia, and called on Senate Republicans to overcome "venom and rancor" and do their job by voting on the nominee.

Some Republican lawmakers, including Senate Majority Leader Mitch McConnell, have said that the next president should nominate a successor to Scalia, a long-time conservative on the court who died Saturday of natural causes, reported NBC News. McConnell says he plans to delay confirming any nomination until after a new president is in office in January.

But Obama said he intends to do his job anyway. "I expect them to do their job as well," the president told reporters at Rancho Mirage, Calif., after a meeting with leaders of Southeast Asia.

"The Constitution is pretty clear about what is supposed to happen. When there is a 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 the nominee or that nominee is elevated to the Supreme Court," Obama said, in what were his first extensive public remarks on the topic.

"There's no unwritten law that says that it can only be done on off years. That's not in the Constitutional text. I'm amused when I hear people who claim to be strict interpreters of the Constitution suddenly reading into provisions that are not there."

There are currently four Supreme Court judges who were appointed by Republican presidents and four appointed by Democratic ones. Republicans worry that Obama's nominee could give the court a liberal majority, and since justices serve life terms, the next judge could rule on critical issues for decades.

Obama didn't hint at whom he may nominate, but said it would be a "well-qualified candidate" who is passionate about democracy, also challenging Republicans to come up with a "plausible rationale as to why they wouldn't even have a hearing for a nominee," according to The New York Times.

Tom Goldstein, who runs the influential SCOTUSblog, believes Attorney General Loretta Lynch, who was recently vetted by Senate Republicans, will be the nominee, according to NBC News.

The president's comments came shortly after Sen. Charles Grassley, the Republican chairman of the Senate Judiciary Committee who holds significant influence over the nomination process, said he will wait to see who is nominated before deciding whether to hold a hearing.

"I would wait until the nominee is made before I would make any decisions," Grassley said, according to Radio Iowa. "This is a very serious position to fill and it should be filled and debated during the campaign and filled by either Hillary Clinton, Senator Sanders or whoever's nominated by the Republicans."