Donald Trump proposed blocking money transfers to Mexico by illegal immigrants until that country agrees to pay for a border wall, pushing immigration policies that have won him votes as he faced likely defeat in Wisconsin's primary on Tuesday.
Trump's campaign said in a memo that if elected to the White House in November, he would use a U.S. anti-terrorism law to cut off remittances from people living in the United States illegally, unless Mexico made a one-time payment of $5 billion to $10 billion for a wall he has proposed along the U.S. border.
The memo elaborated on an idea Trump floated in August, when he suggested seizing all remittances tied to "illegal wages."
Trump released his plan as polls opened in Wisconsin, where U.S. Senator Ted Cruz of Texas appears poised for victory and is presenting himself as a uniter for Republican voters despite a Senate tenure marked by bitter feuds and uncompromising stances.
With Ohio Governor John Kasich running a distant third, Cruz hopes a win on Tuesday will show he can unite the disparate factions of the party. Cruz says he is the only candidate who can beat Trump for the nomination for the Nov. 8 election.
After a week of headlines focused on his missteps and his lag in Wisconsin polls, Trump turned to illegal immigration as a cornerstone of his campaign that is popular with his supporters. The New York billionaire has drawn strong criticism for his harsh rhetoric on Muslims, women and immigration, including his references to some Mexican immigrants as criminals.
The Trump plan detailed on Tuesday cited $24 billion a year in remittances to Mexico from its citizens in the United States, most of whom the campaign said were there illegally. It proposed modifying a financial provision of an anti-terrorism law to require immigrants to prove they are in the United States legally before they can wire money outside the country.
Asked about Trump's remittances plan, Democratic President Barack Obama called it unworkable. "The notion that we're going to track every Western Union bit of money that's being sent to Mexico, good luck with that," Obama said at a White House press briefing.
Some Republicans were also critical.
"It's just another example of why he's an unserious candidate," said U.S. Senator Jeff Flake of Arizona.
Trump said on Tuesday he was "absolutely, 100 percent" behind the wall plan. Talking to reporters as he shook hands with patrons at a George Webb diner in Wauwatosa, Wisconsin, Trump said the $10 billion cost of the wall would be a fraction of the $58 billion annual trade deficit between the United States and Mexico. Mexico has repeatedly said it will not pay for a wall.
Trump also reprised his assault on free-trade deals on Tuesday, and called Ford's plan to invest $1.6 billion to build more small cars in Mexico an "absolute disgrace."
"I think we're going to do very well in Wisconsin," he told reporters. He declined a customer's offer to let him try on one of the dairy state's signature "cheesehead" hats.
The real estate magnate has dismissed Cruz's claim he can unify the party, saying at rallies that "everybody hates Cruz."
And it is an unlikely role for Cruz, who has had a stormy relationship with party leaders since he forced the U.S. government to shut down for six days in 2013 in a budget fight with Obama. But enmity toward Trump among many in the party establishment was enough for five of his former White House rivals to back Cruz.
In the Democratic race, U.S. Senator Bernie Sanders of Vermont has a slender lead in opinion polls in Wisconsin over front-runner Hillary Clinton and is trying to add to his momentum after winning five of the last six contests. He still faces a tough task in defeating Clinton for the nomination.
Cruz told reporters that only he and Trump had the ability to earn the 1,237 delegates from the primary contests necessary to win the nomination outright or to survive a contested convention.
Cruz also rejected talk that establishment Republicans might seek to nominate a new face at the convention, calling it a "fevered pipe dream of Washington that at the convention they will parachute in some white knight."
While Cruz may carry the day in Wisconsin, the road to the nomination does not get any easier for him. The next states to vote, including New York on April 19 and five Northeastern states on April 26, are more Trump-friendly territory.
Trump leads with 737 delegates and Cruz has 475, according to an Associated Press count. Kasich, with 143 delegates, has no chance to gather enough delegates to win on the first ballot but hopes to win support during a contested convention.
In his remarks on Tuesday, Obama took a jab at both Trump and Cruz, saying foreign leaders constantly asked him about "some of the wackier suggestions" made during the campaign.
"I do have to emphasize that it's not just Mr. Trump's proposals. You're also hearing concerns about Mr. Cruz's proposals, which in some ways are just as draconian when it comes to immigration, for example," Obama said.