Donald Trump, the front-runner for the Republican presidential nomination, has promised to deport the 11 million people who live in the United States without the government’s permission. Ted Cruz, Trump’s closest rival, echoes that commitment, while Marco Rubio, who as I write is vying with Cruz to be the anti-Trump, has renounced the “path to citizenship” he used to support and wants to double the size of the U.S. Border Patrol, even as net migration from Mexico has dropped below zero.

On the face of it, the Republican Party is not in a very pro-immigrant mood. Yet the positions staked out by Trump and Cruz are unpopular even among Republicans and could prove fatal to a party that needs support from Hispanic voters to win.

Hostility to immigration is one of the Trump campaign’s most prominent themes. The billionaire reality TV star, who has disparaged Mexican immigrants as criminals, rapists, and drug dealers, promises to end birthright citizenship, stop Muslims from entering the country, triple the number of Immigration and Customs Enforcement officers, “humanely” deport 11 million unauthorized immigrants, and build a wall on our southern border at the Mexican government’s expense.

latinosforthewall_small How to Lose the Latino Vote

Cruz likewise promises to “build a wall that works,” “triple border security,” and boost deportations. When Bill O’Reilly asked him whether he would “round up 12 million illegal aliens,” the Texas senator replied, “Yes, we should deport them.”

During the Republican presidential debate on January 28, Cruz slammed Rubio for getting elected to the Senate as an opponent of “amnesty” in 2010, then supporting a 2013 bill that would have allowed illegal immigrants who met certain conditions to become citizens. The Florida senator desperately tried to distance himself from that bill, saying “there’s not going to be consensus on this issue until we enforce our immigration laws.”

Cruz himself seemed to support some form of legalization in 2013, proposing what he described as a “middle ground” amendment to the immigration bill that would “allow for those 11 million people who are here illegally a legal status, with citizenship off the table.” Cruz now claims the amendment was merely a ploy aimed at showing that Democrats were not interested in bringing unauthorized immigrants out of the shadows so much as boosting the number of voters inclined to support their party.

One reason immigrants like Democrats more than Republicans is that Democrats like immigrants more than Republicans do. According to Pew Research Center polling, Republicans are more likely than Democrats to say immigrants have a negative impact on crime, the economy, and society. Yet Pew also finds that just a quarter of Republicans favor the mass deportation Trump and Cruz promise, while most think “there should be a way for undocumented immigrants to remain in the country.” According to a recent Gallup poll, 79 percent of Americans support work permits or citizenship for unauthorized immigrants and just 19 percent favor mass deportation.

The immigration policies favored by Trump and Cruz are especially unpopular among the growing bloc of Hispanic voters, and that poses a real problem for Republicans. Mitt Romney, who said he would encourage “self-deportation” by making economic conditions intolerable for unauthorized immigrants, won just 27 percent of the Hispanic vote in 2012, down from 44 percent for George W. Bush in 2004.

The polling firm Latino Decisions calculates that the 2016 Republican nominee will need at least 42 percent of the Hispanic vote to win the election. He will not get that by talking up border walls and deportations.