The separation of families at the U.S.-Mexico border and Italy's refusal to let shipwrecked migrants disembark in its ports illustrate the hardening positions on border control in Washington and European capitals.
Lost in the heated political debate is the fact that migrant arrivals in Europe across the Mediterranean from Africa and Turkey are at their lowest level in five years, while arrests on the U.S.-Mexico border - an imperfect but widely used gauge of illegal crossings - are far below levels seen two decades ago.
"Politicians know what moves voters, and this is extremely effective in moving voters."
In both the U.S. and Europe, immigration is increasingly a key political fault line. One side accuses those cracking down on illegal immigration of scapegoating immigrants for problems such as crime and unemployment, even when the correlation is weak.
The other side says politicians are simply recognizing voters' concerns about national identity and poor integration that have long been ignored.
In Europe, the liberal immigration policies that many governments implemented until recently never had widespread popular support, said Ivar Arpi, a conservative editorial writer at Swedish newspaper Svenska Dagbladet.
But because Europeans cared more about other issues, such as the economy or education, there was no serious backlash.
That changed in 2015, when 1 million people - most of them from Syria, Iraq and Afghanistan - crossed into Europe from Turkey and used the lack of border controls in the European Union to roam freely from the Balkans into Austria and onward to Germany and Scandinavia.
That surge and the pressures it put on the destination countries pushed migration to the top of Europe's political agenda, where it has remained since.
"2015 fundamentally changed Europe. But it is hard to know how big a change is when you still are in the middle of it," Arpi said. "Nationalism or globalism, this is the new divide between people. It trumps left-right."
Immigration is a major theme ahead of Sweden's elections in September, just as it has been in a series of European votes in the past two years, including Britain's referendum on leaving the EU.
Far-right and anti-migrant parties have made gains in Austria, France and Germany, while Hungary's Prime Minister Viktor Orban, known for his tough stance on migrants, easily won re-election in April.
Just weeks after taking office in Italy's coalition government, the League - a party vowing to put "Italians first" - has forced other EU nations to grapple with the issue of sea arrivals, which have placed a disproportionate burden on Mediterranean countries in dealing with those seeking a new life in Europe.
Things came to a head when League leader Matteo Salvini, Italy's interior minister and deputy prime minister, closed Italian ports to private ships picking up migrants sailing from North Africa in flimsy boats, saying those volunteer rescuers act as de facto "taxi services" for human smuggling networks.
As a result, two rescue vessels have had to carry rescued migrants on a much longer journey to Spain, and another spent days in limbo off Malta until European countries agreed to share the responsibility for the more than 200 people on board.
The crackdown comes as the number of those trying to make the perilous crossing is dwindling. Sea arrivals in Italy were already down by 80 percent when the new government took office. Across the Mediterranean, about 45,000 migrants arrived by sea in Italy, Greece and Spain in the first half of the year, according to the U.N. refugee agency.