Americans are angry about the border. Here's how it looks on the campaign trail

An eye-popping survey this week helps explain the competing appearances Thursday at the Mexico-U.S. border by the past and present presidents of the United States.

For the first time in its years of polling on the topic, Monmouth University found a majority of Americans supporting Donald Trump's signature policy: A border wall with Mexico.

It's not just Republicans complaining about migration anymore. A clear majority of voters, including swing voters, told the pollster they consider illegal immigration a very serious problem.

That's amid a surge of millions of migrants — not to mention the surge of news headlines about violent acts a small number of them are accused of committing.

Thursday offered a preview of how the presidential candidates will handle the issue. Trump was on the attack; Joe Biden defended his record, then tried countering.

Trump's attack line: Blaming Biden for the migration wave, because the president relaxed several previous border policies, especially in his first year in office.

Biden's retort: Some of those former policies were either immoral, intolerant or impossible to apply permanently. In his telling, he's trying to enact sustainable solutions and being blocked by Trump's Republicans.

"This has become a critical issue," said Patrick Murray, director of the polling institute at Monmouth University. "It has now consumed our political dialogue."

He said the current administration gets its lowest marks from voters on this than on any other issue: "Biden has to do something about it."

Migration frustration: 'This is a big deal'

Another polling analyst said it requires little time in the U.S. to grasp why immigration is now seen even by swing voters as one of the top three most urgent issues in the country.

"All you have to do is turn on your television around the country," said Tim Malloy, polling analyst at Quinnipiac University.

"Pick your network: There are people at the border, there are people sleeping on the streets of New York, there are people staying in hotels that cities are putting them in. And there's a sense that there's a never-ending flow.

"This is a big deal. "

That's the politics of it. And it's one reason, among several, why Biden is now trailing in the vast majority of national and swing-state polls.

The candidates also talked policy during their competing visits to Texas.

Trump listed some of his first-term moves and promised even more aggressive ones if he wins a second term.

Those promises include mass deportations; finishing the wall; using the U.S. military against Mexican drug cartels; and a (likely unconstitutional) refusal to grant U.S. citizenship to children born in the U.S. to undocumented migrants.

Trump found a supportive Border Patrol union. The union leader accompanied Trump on his visit, not Biden. While addressing Trump, Brandon Judd referred twice to his union members as "your agents."

As is his custom, Trump also deviated into unrelated trash-talk. For example, he twice referred to the governor of California, Gavin Newsom, as Governor "Newscum."

Repeated references to violent crime 

Trump went on at length about a shocking murder.

He described a phone call he had with the parents of a 22-year-old Georgia nursing student, Laken Riley, whose head was bashed in during a jog last month.

"She was brutally beaten. Kidnapped and savagely murdered," Trump said. "Joe Biden will never say Laken Riley's name. But we will say it."

Crime is actually down this year in most of the U.S., Democrats will point out; this includes a drop in crime in the cities receiving the most migrants.

They will struggle to make that message heard. A concerted chorus from their opponents is drawing attention to these violent crimes.

On Wednesday alone, Republican lawmakers referred dozens of times, in speeches in the U.S. Congress, to violent acts by migrants.

One Republican made a poster of people allegedly killed by undocumented migrants, placing it behind him during a speech in the House of Representatives.

Riley was one: She was allegedly killed by a Venezuelan-born suspect accused of entering illegally, who was then released after being arrested on an unrelated issue.

A two-year-old toddler in Maryland was recently shot to death, allegedly killed in crossfire that police say included an undocumented migrant with a reportedly long rap sheet.

A Honduran man who allegedly entered the country illegally was accused of raping a teenage girl at knifepoint, and of a separate stabbing incident.

Alleged members of a Venezuelan street gang accused of entering the U.S. illegally were also accused of attacking New York City police officers.

"How many more Laken Rileys are we going to have?" Texas Republican Beth Van Duyne said during a news conference Thursday.

The policies: Democrats versus Republicans

The Democratic response? Trump is peddling a simplistic fantasy, amplified by the reality-distorting echo chamber at Fox News.

The truth is Trump never stopped irregular migration. Millions also crossed illegally while he was president. Then a  pandemic happened, poverty got worse and migration spiked afterward.

They insist real solutions require real — and new — resources. Biden points out that Republicans just blocked a bill that would have delivered some.

"It's time to step up," Biden said in Brownsville, Texas. "[That bill] was derailed by rank partisan politics.… Instead of playing politics with the issue, let's get together and get it done."

The migration system is currently gummed up with logistical shortfalls. Migrants can cross into the U.S. illegally, declare asylum and then have their cases drag on for years.

In the meantime, most are freed. There aren't enough courts and judges to process cases quickly. And there aren't enough facilities and beds to detain everyone indefinitely.

Nor are there enough federal planes to deport everyone. There aren't enough countries willing to accept all these deportations, including Venezuela.

The now-blocked bill included over $10 billion to hire new border agents and immigration judges, and buy new equipment to help with detention and deportation.

Republicans insist the president already has tools he can use. Like executive action to immediately refuse people asylum, which Biden is reportedly considering doing.

But where would everyone be deported to?

When the Republican speaker of the House of Representatives was asked what he'd do if Mexico refuses to accept everyone, Mike Johnson urged Biden to play hardball.

"Mr. President, we're the United States. Mexico will do what we say," Johnson replied.

Republicans also point out, correctly, that they have acted. The House passed a far stricter bill that would virtually halt asylum, and make it easier to deport unaccompanied children.

The Democratic-led Senate won't touch the Republican House bill. Republicans in the House and Senate, meanwhile, killed the above-mentioned bill, which had been negotiated for months between the parties.

American voters will be asked to make sense of all this, and render their verdict in November.