However, Napolitano noted, the Trump campaign's lawsuit alleging it is illegal and unconstitutional is "premature."
"I think Governor Murphy is, just as he was with the lockdown orders and using police to break inside a gym to change the lock on the gym owners while they were sleeping inside, he’s way out there and he’s trying to be ahead of the curve," Napolitano told host Maria Bartiromo.
"I don’t know if this is because he believes this is the right thing to do or he’s trying to gain street [cred] with the crowd at the Democratic National Convention. I hope that other governors don’t follow him."
"The governor of New Jersey has too much power, Maria, and he ought not to be able to do this on his own," Napolitano told host Maria Bartiromo.
"This is a decision for the legislature," he explained. "The Supreme Court has ruled that when it comes to electing electors, choosing electors to vote in the electoral college for president, which is what we are talking about even though you would vote for Donald Trump or Joe Biden, you’re actually voting for electors in the electoral college, the states can do it, the state legislators can do it however they want, not the governor, the legislatures."
Napolitano, who lives and votes in the Garden State, said the governor's executive order allows for in-person voting but also requires a ballot to be sent out, which can be submitted by mail.
"If you’re honest, you’re not going to vote twice. If you’re dishonest, you have the opportunity to vote twice," he said. "Voting twice is, of course, a felony meaning punishable by more than a year in jail."
The former judge of the Superior Court of New Jersey questions why Murphy would do this "prematurely" when New Jerseyans voted in a primary in July.
"I don’t know if it’s a prudential judgment on his part or a political judgment on his part, however, I don’t think the lawsuit will prevail because it’s premature," Napolitano said. "Judges don’t exist in order to say this is right, this is wrong, you can't do that. They exist to resolve real disputes where someone has been harmed and nobody's been harmed yet."
Trump has said mail-in voting is opening up to large-scale election fraud.
"Nobody can blame the president for being worried about it," Napolitano said. "The Democrats should be worried about it, too. A fraudulent election is a fraudulent election. It can go either way."