If no one much cared about immigration, it would be a relatively easy problem to fix. The United States economy is so large that the Bureau of Economic Analysis recently announced that new models of calculation show that our economy is 3 percent bigger than previously thought and no one seemed to really notice. But that $450 billion adjustment is more than the GDP of most of the countries in the world.

As in any underground economy, no one really knows how many illegal immigrants there are in the United States, but the number most often cited in 11 million. (And please, let’s don’t dumb down language by insisting on calling those who are in fact here illegally “undocumented.” If I’m travelling abroad in a country that requires a visa and lose my passport, I’m undocumented. If I enter that country without a visa, I’m illegal.) In a population of over 313 million, that’s not a huge number—just over 3 percent, making up about 5 percent of the civilian workforce, according to Pew.

For example, there are over half a million Farsi-speaking Iranian immigrants (mostly here legally) in the Los Angeles area nicknamed Tehrangeles, yet most Southern Californians are oblivious to hosting what amounts to a good-size Iranian city. America is a big place, and it can absorb a lot without most of us even noticing.

Indeed, for much of the country, illegal immigration is a small issue or a nonissue entirely. There are only 12 states where Pew estimates that illegal immigrants make up more that 4 percent of the population. Put it this way: in all but a few states, there are more attendees of college football games than there are illegal immigrants.

But in California and Texas, two giants of the American economy, illegal immigrants make up almost 10 percent of the labor force; in Arizona, Georgia, Nevada, and New Jersey, their share is over 7 percent. For many Americans, illegal immigration is a significant economic reality.

I call illegal immigration a “reality” rather than a “problem” because of the huge differential in the economic impact of illegal immigrants depending on the sort of work you do. For unskilled American workers without a high-school degree, illegal immigrants have helped drop the wage floor by as much as 7 percent, according to The New York Times—a hefty penalty imposed on those who are least likely to be able to afford it, or to compensate by acquiring new skills or changing jobs. But among skilled and educated workers, illegal immigrants have helped raise incomes by as much as 10 percent, again according to the Times; by driving down the costs of unskilled labor, there are more dollars remaining to go to skilled workers.

In other words, the American citizens hurt by illegal immigration are the ones who are already the most vulnerable, and none of the proposals currently being considered is likely to change this dynamic. Nothing being considered would reduce the large pool of unskilled workers competing for the same positions, whatever their legal status.

For an issue that has generated such passion and debate, the range of realistic public-policy proposals on immigration is relatively narrow. No one is suggesting removing the 11 million illegal immigrants from the U.S. Alternatively, there is no momentum for an “open borders” policy in which, say, Mexico, Canada, and the U.S. would allow citizens to live and work in all three countries, per the European Union model.

With those borders standing, few are arguing, at least persuasively, against the need for stronger border controls. Where resources have been invested in fencing and manpower, the number of illegal border crossings drops dramatically. As a Sunday New York Times headline put it (perhaps while trying to make a different point): As U.S. Plugs Border in Arizona, Crossings Shift to South Texas.

So what are we arguing about? The fault line is moral as well as practical. Excepting a relatively small number of children, every illegal immigrant in the U.S. entered knowing they were breaking the law. Should they be rewarded for doing so?

With over 30 million legal immigrants currently living in the U.S.—a record number—no thinking person can seriously argue that the U.S. is anti-immigrant. We lead the world in legal immigration by every possible measure. We are one of the few countries in the world that even grants automatic citizenship to children of those who broke the law to come here. We may consider that normal, but most countries, including all of the European Union, consider it terrible policy. Health care may be considered a right in France and Germany, but instant citizenship to children of nonresidents is not.

If you sucked all the passion and politics out of the illegal-immigration debate, reasonable solutions would be apparent. The majority of Americans believe it is wrong to reward illegal immigrants for breaking the law, which is why so few elected officials dare use the word “amnesty.” At the same time, most Americans agree that the 11 million illegal immigrants are here to stay and some basic “reform” must deal with their status.

Which brings us to Sen. Marco Rubio and his role in the immigration debate. I can understand not agreeing with the Gang of 8 proposals, because I don’t agree with all of them. I come down on the “right” side of the center-right on the dangers of rewarding illegal behavior. But what I don’t get is the viciousness with which some on the conservative side are attacking Rubio and other conservatives like Sen. Kelly Ayotte of New Hampshire.

I’m old-fashioned enough to believe anyone who is trying to solve a tough problem in good faith deserves some respect. And I’m realistic enough to know that a lot of good Americans disagree with my conservative views on immigration. And I’m practical enough to know that the immigration status quo is going to change, and if conservative Republicans like Rubio and Ayotte don’t help to shape that change, it will be left to the liberals.

The politics of immigration are much more complex than most seem to admit. “Solving” immigration won’t magically cure the difficulties Republicans have been having with Hispanics. But being perceived as anti-immigration is a terrible place to be in a country of immigrants. The Obama administration has deported far more illegal immigrants than the “Dream Act” has allowed to remain, but there’s no question that Obama’s last-minute executive order on the Dream Act was a skillful ploy that energized Hispanic supporters. When Mitt Romney referred to “self-deportation” of illegal immigrants, it was meant as a contrast to a policy of forced deportation that has accelerated under Obama.

Hispanics have consistently suffered significantly higher rates of unemployment in the Obama years than the general population and yet 71 percent of Hispanics voted for Obama. For all the talk of Obama’s success with young voters last year, the reality is that Obama’s margin of victory with young voters came from the same Hispanic and African-American voters who have suffered through a record level of unemployment in the Obama economy. Romney actually carried white voters under 30 by a comfortable margin. The Republican problem with young voters is less a function of age than an acceleration of the problems Republicans have across the board with non-white voters.

Rubio and Ayotte are conservative Republicans who won races in purple states, and would easily win reelection tomorrow. They are in great shape, but the image of Republicans with Hispanics is not. It’s hard to figure how attacking those who are trying to solve a problem is going to help Republicans with those who are most affected by the problem.

In 2000, we made an ad for George W. Bush that began, “Why don’t the hard problems get solved? Because they are hard.” That was never truer.

It’s easy to be a liberal Democrat and line up with the most liberal immigration reforms. It’s a lot harder to be a conservative Republican and fight the trench warfare of making an immigration bill more conservative. That’s what Rubio and Ayotte are trying to do, and it seems to me Republicans should be glad they are in the fight.