This is particularly true on immigration, a serious problem that should be amenable to a bipartisan solution.  Instead, the candidates have so demonized the issue that it has become toxic even to talk about practical solutions. Sen. Marco Rubio may be the most prominent GOP presidential contender who has walked away from previous compromise positions, but he’s not the only one.

The candidates are, in effect, allowing a reflexive anti-immigrant minority within the Republican party to dictate its conception of ideological purity when in fact there is a rough bipartisan consensus on what must be done. The Senate, in June, 2013, actually passed a bipartisan bill 68-32, with 14 Republican votes, the result of tough and arduous negotiations. No one thought it was perfect. But most thought it addressed the key issues, from stronger border security to sanctions for employers hiring illegal workers to bringing undocumented persons already here out of the shadows and into the tax-paying community.

Yet the GOP-controlled House never voted on it. And now it’s being talked about in the campaign as if it’s a treasonous document. This harsh rhetoric results in a caricature of the debate—“make everyone a citizen” vs. “send ‘em all back”—that bears virtually no resemblance to what’s at stake.

Seen through a bipartisan lens, the issues look very different. Both sides have moral and practical starting points. Conservatives say it is wrong to reward illegal behavior and, as a practical matter, doing so would encourage more immigrants to sneak across the border or overstay their temporary visas. Liberals say it is a practical impossibility to deport 11 million people, and it would be wrong and inhumane to tear apart families who have been thriving here for years or to punish children who were brought here by their parents.

In addition, both sides can agree that we need to address both the “push” and the “pull” of illegal immigration. Many of the Mexicans coming here are being pushed by lack of economic opportunity, while many of the Central Americans, including the most recent wave of unaccompanied children, are fleeing horrific gang violence. There is no guaranteed solution to these problems, but both liberals and conservatives have an interest in exploring what could be done in terms of trade, investment, aid, perhaps some security assistance, as well as rethinking our refugee policy.  It’s a situation that cries out for bipartisan cooperation.

What draws immigrants here, of course, is safety and economic opportunity, the strengths of our country. Immigrants have added to that strength by bringing skills, ambition, and manpower and keeping our population far younger than most other developed countries.  The trick is to promote legal immigration over illegal. You won’t know from listening to the campaign rhetoric, but the bipartisan Senate bill has a plethora of proposals. It doubles the number of border patrol agents, adds hundreds of miles of border fencing along with all kinds of high-tech surveillance equipment, requires all employers to electronically verify legal status with stronger penalties for violators, sets up a new electronic system to catch temporary visa holders who try to over-stay, etc. At the same time, it gives new incentives to high-skilled immigrants and investors, makes it easier for U.S.-educated foreigners to stay, creates a new guest worker visa and a new farm worker visa, and modifies the family visa program. It’s an example of politics as “the art of the possible.” It’s one thing to say the package could be improved. It’s quite another, as some hardliners seem to imply, to say that it was wrong even to attempt a bipartisan negotiation.

Of course, the most toxic issue in the debate is what to do about the 11 million undocumented immigrants already living and working here. “Amnesty” has become the biggest slur in the hardliner lexicon, even though a poll taken soon after the Senate bill passed showed 65 percent of Americans would favor some path to citizenship if "they pay a fine, any back taxes, pass a security background check and take other required steps." It is also important to remember that President Reagan, two years before he signed a sweeping immigration bill, said, "I believe in the idea of amnesty for those who have put down roots and lived here, even though sometime back they may have entered illegally.” The bipartisan Senate bill offers a tortuous 13-year path to citizenship, requiring fines, back taxes and learning English, bars legal status to those with records of drunk-driving convictions, gang activity, domestic violence, passport fraud, and identity theft, and other strictures. Yet by crying “amnesty,” the hardliners simply turn their backs on the serious bipartisan effort in the bill to address both sides’ deep concerns.

Immigration was a problem when the 2007 reform effort failed. It was a problem when the Senate’s 2013 bill failed, and it remains a problem today. It will remain a problem until partisans on both sides recognize the only solution is a bipartisan one.

Jay Branegan serves as a Senior Fellow at The Lugar Center.