A Fox News correspondent and former judge has claimed governors' stay-at-home orders are "unconstitutional" and would not hold up in court.

Andrew Napolitano made the claim on Fox & Friends on Tuesday as protesters across the US gather to challenge stay-at-home orders in their own states.

"Well the government can't nullify the Bill of Rights, meaning the government can't stop you from expressing your opinion about the government. It can't stop you from assembling in public as long as it's peaceful and you're not contagious,' he said.

"The government has to recognise that the rights that are in the Constitution still exist in bad times as well as in good and it has to treat people equally."

Anger has increased among some US residents as stay-at-home orders continue for a majority of the states. Although these protesters are in the minority, with 60 per cent of Americans in support of keeping stay-at-home orders, according to a NBC News/Wall Street Journal poll, these protests have still made waves in the country.

The purpose of the protests are to put pressure state governors to reopen parts of the economy amid the pandemic. But health experts have warned reopening too early could cause a deadly resurgence of the novel virus.

Mr Napolitano argued the state governors had no right to issue stay-at-home orders from the beginning, even though the constitution gives states the power to maintain public safety and order.

In the last 100 years, the Supreme Court has also upheld states' authority over residents, even when it restricted freedoms, the New York Times reported.

One case that best explained the power of states happened in 1905 during the smallpox epidemic: Jacobson v Massachusetts. In the case, a pastor argued that a mandatory smallpox vaccination violated his constitutional rights. It was required for him to get vaccinated in his state or pay a fine. But the Supreme Court ruled in favour of the state.

"The liberty secured by the Fourteenth Amendment, this court has said, consists, in part, in the right of a person "to live and work where he will,"' the Court wrote.

But it added: "In every well-ordered society ... the rights of the individual in respect of his liberty may at times, under the pressure of great dangers, be subjected to such restraint, to be enforced by reasonable regulations, as the safety of the general public may demand."

Mr Napolitano acknowledged police and state legislatures would continue to enforce stay-at-home orders across the US until each area reopened, but legal fights might happen later.

"Once these cases are tried there isn't a judge in the country to recognise the power of a governor or mayor to make up a law off the top of their head," he claimed.