"For Donald Trump, this is a moment of triumph. Three justices in the three and a half years -- all of a similar intellect and all of a similar attitude about the Constitution," the former judge said on "Fox & Friends Weekend."
"Very few presidents have had this many nominees and Donald Trump is still in his first term," Napolitano added. "He has been utterly faithful to his promises with respect to the intellect and ideological orientation of the people that he has nominated."
The president is expected to announce his pick to fill the seat vacated by the death of Justice Ruth Bader Ginsburg on Saturday afternoon, and multiple sources tell Fox News that Amy Coney Barrett is expected to be his nominee.
Napolitano says Barrett, who would be Trump's third Supreme Court nominee, is a "conservative intellectual, sort of in the Neil Gorsuch mold that President Trump has been promising he would nominate."
He pointed out Barrett, now 48, who was appointed by Trump to the 7th Circuit U.S. Court of Appeals in Chicago in 2017, graduated from the same law school as him -- Notre Dame -- and said she has very little track record but has articulated very strong opinions.
"She has already argued that Roe v. Wade, the abortion decision, was wrongfully decided. She has also said she will respect stare decisis, laws that are well-settled and would not vote to change them other than in the most profound and significant situation. So she’s going to be grilled on that," he said.
Napolitano also reacted to a draft bill introduced Friday by Rep. Ro Khanna, D-Calif., proposing 18-year term limits for the Supreme Court, among other changes.
"Representative Ro Khanna's problem is not with Donald Trump, and it's not with the electorate," Napolitano said. "It's with the Constitution ... legislation can't change the Constitution," which "prescribes that federal judges ... serve for life."
Napolitano added: "I can't imagine Rep. Ro Khanna would be doing this if Joe Biden were appointing, fill-in-the-blank, a liberal justice."