Four years after Republicans embraced Donald Trump’s nativist and often racist playbook in an attempt to keep control of Congress, the party is once again placing the volatile politics of immigration at the center of its midterm election strategy.

From the US-Mexico border to the US Capitol, in hearing rooms and courtrooms, Republicans are hammering the issue. At the forefront of the debate is a once-obscure public health order invoked by the Trump administration in March 2020 ostensibly as a means for controlling the spread of the coronavirus along the south-western border.

Seizing on a decision by the Biden administration to lift such “Title 42” border restrictions, Republicans have sought to paint Democrats as pursuing an extremist immigration agenda that they say has cost the nation its very sovereignty.

The provocative and often misleading messaging campaign was on full display when Alejandro Mayorkas, the secretary of homeland security, testified on Capitol Hill.

For more than eight hours, across two days, Republicans pelted Mayorkas with accusations and insults, demanding he accept the blame for what they described as dangerous and dire conditions along the 2,000-mile border with Mexico.

“We’re all really border states now,” Congressman Steve Chabot of Ohio said darkly.

In another tense exchange, Ken Buck of Colorado said his constituents believed Mayorkas was guilty of treason and deserved to be impeached – something conservatives have vowed to pursue if they win the House.

“What you have just said – it is so profoundly offensive on so many different levels, in so many different regards,” Mayorkas responded, visibly upset.

Mayorkas forcefully defended the administration’s handling of the border and said it was up to Congress to act.

“We inherited a broken and dismantled system that is already under strain,” Mayorkas said. “It is not built to manage the current levels and types of migratory flows. Only Congress can fix this.”

The hearings laid bare the tensions within Democratic ranks over Biden’s immigration actions, particularly over Title 42.

For months, immigration advocates and progressives have been pressuring Biden to lift Title 42, which gives officials the authority to swiftly expel migrants trying to enter the US instead of allowing them to seek asylum and remain in the country while their claim is evaluated.

“You’re essentially doing policymaking by crisis,” said Claudia Flores, an immigration policy expert at the left-leaning Center for American Progress thinktank. “And that’s just not effective.”

As a matter of public policy, Flores said, it was dangerous to use a public health order to control immigration. Not only was the rule insufficient for addressing problems at the border, she added, but it had carried “grave humanitarian consequences” for asylum seekers.

But some vulnerable Democrats have appealed to Biden to hold off on lifting the order, fearing it could be a political liability ahead of a difficult election cycle. Agreeing with Republicans, they have expressed concern that the administration lacks a comprehensive plan for dealing with the anticipated increase in migrants making asylum claims when the order is lifted in late May.

“This is not good for Democrats in November,” the Texas congressman Henry Cuellar, a Democrat facing a progressive challenge for his border-district seat, told Fox News Digital.

“You know, in talking with some of my Republican colleagues, they’re saying, ‘We can’t believe the White House is giving us this narrative. We can’t believe that they’re hurting Democrat candidates for the November election.’”

In his testimony, Mayorkas argued that his department had a plan to handle the expected surge of migrants. He repeatedly directed lawmakers to a six-point plan, released in advance of the hearings, that outlined a more aggressive effort to enforce immigration laws after the public health rule is lifted. It also included efforts to partner with non-profits that help migrants in the US while their cases are processed and to work with countries across the region to address “root causes” of migration.

“When the Title 42 public health order is lifted, we anticipate migration levels will increase, as smugglers will seek to take advantage of and profit from vulnerable migrants,” the memo stated.

It did little to appease Republicans and some Democrats.

“It’s clear to me that the federal government is not prepared – not even close,” Greg Stanton of Arizona, a border-state Democrat, said during the hearing.

Biden has worked to reverse many hardline policies that were at the heart of Trump’s “zero tolerance” approach to immigration. The number of migrants attempting to cross the border has risen sharply.

Biden has argued that the only way to address the migration is at the source – an ambitious plan that will probably take years to bear fruit. In the short term, his administration faces acute operational and political challenges.

At a White House meeting last week, members of the Congressional Hispanic Caucus urged the president to stand firm behind the decision to end the public health order.

“Title 42 must end on 23 May,” the California congresswoman Nanette Barragán, a deputy chair of the CHC, said she told the president, while urging him to “not support legislation to extend the end-date”.

With the prospects of legislative action dim ahead of the midterms, the caucus is urging Biden to use his executive authority to make good on some of his promises to Latino voters on immigration, the environment, healthcare and the economy. They have argued that it is both good policy and good politics, as Latino support for Democrats is waning amid concern over the economy and inflation.

“After four years of traumatic, xenophobic and inhumane immigration policies being forced on our most vulnerable communities, we have a duty to deliver them the protection and support they and their families so desperately need,” the Democratic congressman Adriano Espaillat, of New York, said after the meeting.

Fears over Title 42 are only one element of the Republicans’ messaging. Republicans have sought to tie illegal immigration to other potent themes like voter fraud and crime. Allegations of undocumented migrants voting in large numbers have been repeatedly disproved. Studies have found that migrants commit crime at lower rates than native-born citizens.

Republicans have long used immigration as a political weapon – with mixed results. In 2018, they lost the House in a wave election fueled in part by fury over Trump’s hardline policies that separated migrant children from their parents. The same year they expanded control in the Senate.

The political winds have reversed. Republicans are heavily favored to take the House, and possibly the Senate. The national mood has soured on Biden and the Democrats as concerns over the economy and inflation deepen.

But even as economic discontent dominates political debate, polling suggests immigration remains a pressing issue, particularly for Republicans. Four in 10 Americans, and nearly 70% of Republicans, say they worry a “great deal” about illegal immigration, according to a Gallup survey.

During a tour of the border in Texas last week, the House minority leader, Kevin McCarthy, chided a reporter for asking about his false claim that he never urged Trump to resign after the January 6 insurrection – comments captured by an audio recording.

“After all this, that’s what you want to ask?” he said. “I don’t think that’s what the American people are asking. I think they want to know about what’s going to happen here and how we’re going to secure the border.”

Democrats blame Republicans for whipping up fear while standing in the way of reform. It has been almost a decade since Congress seriously considered immigration reform, a bipartisan plan that was derailed by House conservatives.

“Let me tell you why our Republican colleagues don’t want to do their job – why they won’t work with us or vote for any of the bills that we have brought forward in the House,” the Texas congresswoman Veronica Escobar said. “It’s because the status quo works for them.”

“They love Title 42,” she said, arguing that it “helps them push this xenophobic rage machine that they believe will help them get elected and re-elected”.

It is unclear how the administration plans to proceed if a court rules it cannot lift Title 42. Biden declined to say whether he would sign legislation delaying the removal, which is under consideration by a bipartisan group in Congress.

Vanessa Cardenas, deputy director of America’s Voice, a pro-immigration group, said Democrats must be more aggressive in defending their vision for reform. Keeping Title 42, she said, would not only play into Republicans’ hands, but would be a major disappointment to voters, particularly Latino voters who helped Democrats win in 2018 and 2020.

“In an election season where margins matter, in states like Arizona, Nevada and Georgia, where the presence and the vote of the Latino community can make a difference, it’s really important that Democrats are able to articulate a vision that is in contrast to the other side,” Cardenas said.

Referring to Trump’s hardline adviser, she added: “A Stephen Miller-Lite approach to immigration is not going to motivate the base.”