9 Immigration Questions That Sanders And Clinton Haven't Been Asked In The Democratic Debate

"The big takeaway thus far has been that making big immigration promises without a strategy to pass legislation will not pass muster," said Ali Noorani, executive director of the National Immigration Forum, which works with business, law enforcement, and faith leaders.

If a legislative solution comes first, how will Clinton and Sanders get Congress to work with them?

"You can't fix the entire immigration system through executive action," he said. "At some point you need to govern."

"What would you do to get Congress to act on immigration reform?" said NCLR president Janet Murguia. "How would you bring them to the table, particularly given the dynamics in the House?"

For-profit prisons and detention centers house undocumented immigrants. Clinton said she would phase out detention centers and adopted the policy after pressure from groups and a meeting with the organization Color of Change.

But Politico reported that Richard Sullivan who was until November a federally registered lobbyist for "for-profit prison operator GEO Group-bundled $69,363 in donations for Clinton in the fourth quarter, bringing his total for the year to a whopping $274,891."

The campaign policy rejecting donations from the private prison business only includes direct donations to Clinton's campaign. Should it extend to lobbyists who fundraise, too?

Sanders has said he would return veterans and immigrants deported during Obama's presidency to the United States. How would he do this in practice? How would a program be able to verify who was returning? And how would he get Republicans to agree to this?

During Obama's fight for the Affordable Care Act, the law was carefully written so as to avoid giving benefits to undocumented immigrants because health care is already controversial without adding in the politics of immigration. Is Sanders' plan realistic?

Democrats and Republicans often note (bipartisanship!) that the push for major changes to the U.S. immigration system was undertaken chiefly because, the "immigration system is broken." But too often, Republicans say, the conversation around immigration alienates people who want to do it "the right way."

What changes would the two candidates make to that system? And what would they be willing to give up in exchange for a legislative solution?

"If you have a Congress that isn’t going to work for you and is going to be obstructionist, what will you do to make the legal immigration system work better?" said immigration lawyer David Leopold, who has worked with national immigration groups.

Sanders has come under some scrutiny this year for his past votes on immigration bills in Congress — and the way he has talked about the effect of immigration on American wages, for instance, or that the idea of "open borders" is something espoused by the Koch brothers.

Javier Palomarez, the president of the U.S. Hispanic Chamber of Commerce (USHCC), said Sanders talks about income inequality, but during a Q&A with the senator and the USHCC Sanders "claimed immigrant workers depress American wages."

"Why should Hispanic voters trust [Sanders] on immigration?" Palomarez said to BuzzFeed News.

This tension has been at the center of Obama's presidency: He expanded the power of executive action and deferred the deportation of millions of undocumented immigrants — but he also has come under intense scrutiny throughout his presidency from activists for the number of deportations.

In a gridlocked Congress, immigration legislation has stood out for having had broad bipartisan support twice in the last decade. But Obama in 2008 famously chose to focus on health care rather than immigration, which former White House chief of staff Rahm Emanuel called a "third rail." Would either candidate commit to using limited political capital on immigration first?

O'Malley didn't move the dial with voters and suspended his campaign Monday but he was hailed by immigration advocates and influential voices like Ramos for his immigration plan that kept Clinton honest and saw Sanders playing catch up in the Fall.

Gabriela Domenzain, his deputy campaign manager, said she would ask Clinton why she helped kill driver's licenses for undocumented immigrants in New York state during the 2008 election.

"How can Latinos trust you when in an election year you killed a long and hard fought battle that Spitzer was willing to shepherd?" she said, referring to the disgraced former New York governor who told David Axelrod in the Fall that her campaign wanted the issue scrapped in 2008. Clinton's comments at the time and waffling during a debate were widely seen as a major gaffe.

Domenzain said her question for Sanders would be why he voted for a 2006 amendment introduced in the House, banning American officials from tipping off the Mexican government about the whereabouts of Minutemen patrols, itself based on a rumor making its way around the fringe parts of the immigration debate.

"It was election year kowtowing to the nativists and Bernie voted to make that cooperation illegal," she said. "I would like to hear him explain that."