Republican U.S. Senate candidate Jason Lewis has joined a growing list of litigants challenging the Walz administration over the Minnesota governor's shutdown orders to curb the spread of the coronavirus.

Lewis' lawsuit, filed Tuesday, is the second federal legal challenge to Gov. Tim Walz's amended executive order in as many days: On Monday, the Upper Midwest Law Center filed suit on behalf of churches asking a judge to fully reopen places of worship.

Attorneys for the state also will be in court later this week in an enforcement action against a Stearns County bar owner who sought to reopen his chain of restaurants on Monday in defiance of the governor's emergency orders.

Those cases follow a challenge brought last month by the Free Minnesota Small Business Coalition, a group of small-business owners asking the Minnesota Court of Appeals to strike down a series of executive orders that forced them to close their businesses.

Lewis, challenging DFL incumbent Sen. Tina Smith, is seeking an order stopping Walz from enforcing his orders limiting public gatherings and temporarily shuttering bars, restaurants and other types of businesses that bring people into close contact.

The former radio talk show host and congressman has made the pandemic restrictions a focus of his campaign, speaking out on a statewide RV tour and joining protesters outside the governor's residence last month. His senior counsel, Justin Clark, also serves in the same role for the re-election campaign of President Donald Trump, who supported the protesters.

"What started as a fight against an invisible danger has morphed into a fight against a very clear and present danger, and that is a fight against unconstitutional power grabs being waged by radical liberals like Senator Tina Smith and Governor Tim Walz," Lewis said in a statement Tuesday.

Walz spokesman Teddy Tschann said the governor's orders are legal measures to protect the public during the pandemic.

"The virus has forced the state to take drastic action to keep Minnesotans safe, but it's action that is within the Governor's authority," he said in a statement. "It is also in line with federal guidance and similar to what many other states are doing."

He added that the governor is seeking to "find ways to get Minnesotans back to work and to a place where they can safely gather in large groups."

Walz revised his order on May 13 to allow certain businesses to reopen and let people gather in groups of 10 or fewer. Lewis argues that the requirement that no more than 10 people can gather "severely limits" his ability to engage in campaign activities and creates "an unconstitutional ban on travel that violates the U.S. Constitution."

State Attorney General Keith Ellison called Lewis' lawsuit "a frivolous, political lawsuit about how the pandemic has inconvenienced him personally while Minnesotans are caring for each other by staying safe at home."

Ellison has also gone on the offensive to enforce Walz's orders. His office is suing Kris Schiffler, owner of Shady's Hometown Tavern and Event Center in Albany, Minn., after Schiffler publicly vowed to reopen Monday in violation of Walz's order. A judge issued a temporary restraining order blocking Schiffler from opening and set a court hearing for Friday.

In a recent interview, Ellison said he anticipates the need to defend the governor's executive order as long as it remains effect.

"It is an order designed to promote good health and life," said Ellison, whose mother died in March from complications of COVID-19. "My first argument is not a legal one, my first argument is don't you want to protect your family? Don't you want to protect yourself? This is what it's about."

Twitter: @smontemayor