CNN  — 

The Democratic rebellion against President Joe Biden’s plans to lift pandemic-era border restrictions is growing, as candidates in marquee races from Nevada to New Hampshire break with the administration and Republicans turn immigration into a centerpiece of their midterm election messaging.

The Biden administration is set to roll back next month the public health authority known as Title 42, which was first invoked by then-President Donald Trump. The measure allows border authorities to turn migrants back to Mexico or their home countries because of the public health crisis.

Democratic senators in Arizona, Georgia, Nevada and New Hampshire – all top GOP targets this year – have already sought to distance themselves from Biden’s move, charging that the White House has not adequately planned for a surge in border crossings.

That criticism expanded this week into governor’s races in two Southwestern swing states, Arizona and Nevada. Katie Hobbs, the Arizona secretary of state and front-runner for the Democratic nomination for governor, urged Biden to reverse his “rash decision” and said lifting Title 42 “without a clear plan to secure our border would be a disaster.”

In Nevada, Democratic Gov. Steve Sisolak warned the President in a letter of a “humanitarian crisis” at the southern border if the public health authority is repealed without a “comprehensive plan.”

Republicans, meanwhile, are pouncing on the issue.

The National Republican Senatorial Committee, the Senate GOP’s campaign arm, on Thursday launched a $1 million television advertising campaign tying Sen. Mark Kelly to Biden’s move because of the Arizona Democrat’s August vote against an amendment that would have required the Department of Homeland Security to expel migrants who illegally enter the country and may contribute to the spread of Covid-19.

“Kelly voted to allow restrictions to be lifted, which will cause a massive new border surge,” a narrator says in the ad. “Tell Sen. Kelly: Stop voting with Biden and against Arizona.”

Kelly campaign spokeswoman Sarah Guggenheimer countered by saying the senator “has delivered increased border security resources, introduced bipartisan legislation to address the crisis, and has stood up to both the Biden administration and his own party to ensure a safe, humane, and orderly process at the border.”

Biden administration on defense

The Biden administration is on track to end Title 42 on May 23. The decision, made by the US Centers for Disease Control and Prevention, ignited concerns about a migrant surge.

Homeland Security Secretary Alejandro Mayorkas told CNN this week his department has “plans” to address the expected surge. But he would not elaborate.

“I think we have to be very mindful of the fact that we are addressing enemies, and those enemies are the cartels and the smugglers, and I will not provide our plans to them. We are going to proceed with our execution, carefully, methodically, in anticipating different scenarios,” he said.

Vulnerable Democratic lawmakers plan to use a House Judiciary Committee hearing featuring Mayorkas next week to distance themselves from the Biden administration’s decision, congressional aides say. They plan to grill the secretary, whose answers could offer a window into how the White House will defend its position.

White House press secretary Jen Psaki said Wednesday the administration was “planning and preparing” for the May 23 rollback of Title 42 but remains open to conversations with lawmakers about immigration reform.

More than 20 states, mostly GOP-led, on Thursday asked a federal judge in Louisiana to immediately block the administration from ending Title 42. The administration on Friday asked the judge to deny the request.

The Democratic divide over Title 42 pits candidates in swing states and vulnerable incumbents against not just Biden’s White House but more progressive Democrats and immigration advocates.

Senate Majority Leader Chuck Schumer of New York is among the most vocal advocates of ending Title 42 border restrictions. Last month, Schumer, along with Democratic Sens. Alex Padilla of California, and Bob Menendez and Cory Booker of New Jersey, said there was “no public health benefit to sending asylum seekers back to harm” and urged Biden “to stop breathing new life into this inhumane Trump policy.” Three weeks later, the administration announced it would lift the pandemic restrictions.

Some Democrats up for reelection this year, such as Georgia Sen. Raphael Warnock, have faced condemnation from the left for criticizing Biden’s move to roll back Title 42.

Kelly and New Hampshire Sen. Maggie Hassan, who both visited the US-Mexico border earlier this month, signed on to a Republican-backed bill that would delay the rollback.

Nevada Sen. Catherine Cortez Masto, who has also urged Biden to reconsider his plans, has faced criticism from Republicans for signing a June 2020 letter that urged Trump to back off what the letter called a “CDC asylum ban.”

Michigan Sen. Gary Peters, who chairs Senate Democrats’ campaign arm, said this week that the Biden administration might need to delay the rollback of Title 42 until a clearer plan to mitigate the flow of migrants at the southern border is in place.

The Senate Homeland Security Committee chairman said he understands why his colleagues running for reelection might be willing to come out against Biden.

“I think they are right to raise questions. This is a very serious issue,” said Peters, who is not up for reelection this year. “The senators have to take a position that they think is best for their state.”

Criticism across the midterm map

Meanwhile, Democratic opposition to the Biden administration’s move has mounted across the map of competitive Senate races in November’s midterm elections.

In Pennsylvania, Lt. Gov. John Fetterman, an otherwise strong supporter of Biden’s policies, broke with the White House on Title 42.

“I think there should be a little bit more thought given into that. And I don’t think we’re quite there just yet, quite frankly,” Fetterman said in an interview.

US Rep. Conor Lamb, another Senate contender in Pennsylvania, told CNN he is a “skeptic” of the planned rollback.

“I will certainly listen to any argument that the administration wants to make,” Lamb said. “But you know, the pandemic is not over. That’s why Title 42 went into place was to just try to help control what was happening down there in light of the pandemic and how things can spread and particularly with these different variants.”

In Wisconsin, Democrats hoping to unseat Republican Sen. Ron Johnson this fall lambasted Biden over Title 42.

Lt. Gov. Mandela Barnes, state Treasurer Sarah Godlewski and Milwaukee Bucks executive Alex Lasry have all called for the administration to offer a plan to keep both asylum seekers and US residents safe before lifting the public health authority.

Florida Rep. Val Demings, who is challenging GOP Sen. Marco Rubio, was a top contender for Biden’s running mate in 2020. Her campaign spokesman Christian Slater said Demings, a former Orlando police chief, did not support lifting Title 42 “until there is a plan to put more boots on the ground and support our law enforcement officers at the border.”

Democratic Senate candidates in red-leaning states have also spoken out.

Ohio Rep. Tim Ryan, the leading Democrat in an open-seat Senate race, has co-sponsored a bill that would prevent the Biden administration from what he calls a “wrong and reckless” decision to lift the Title 42 restrictions.

“Prematurely ending this policy without a path forward does nothing to keep Americans safe, support our Border Patrol agents, protect asylum-seekers, or bring about the comprehensive fix our immigration system needs,” Ryan said.

And retired Marine Lucas Kunce, a top candidate for the open seat in Missouri, said, “Repealing Title 42 with no actual plan isn’t policy – it’s politics.”

CNN’s Lauren Fox, Priscilla Alvarez, Manu Raju, Paradise Afshar, Andy Rose and Kate Sullivan contributed to this report.