Those unalterably opposed to immigration reform make two arguments, neither of which stands up to scrutiny. Backers of the Gang of Eight plan are smartly now calling their opponents on the carpet.

Sen. Marco Rubio (R-Fla.) (Alex Wong/Getty Images) Sen. Marco Rubio (R-Fla.) (Alex Wong/Getty Images)

Obviously, certain outside groups opposing the Gang of Eight dislike all forms of immigration (not to mention population growth). But anti-reform pols are cagier. In the Wall Street Journal, Jason Riley observes that Republican Sens. Jeff Sessions (Ala.) and Chuck Grassley (Iowa) claim they support legal immigration but their records say otherwise:

The record shows that Mr. Grassley has been a consistent critic of the H-1b visa program for foreign professionals who want to work in the U.S. He has opposed lifting the visa cap. He has put holds on legislation that would speed the process for hiring foreign nationals who come here legally, and he has supported per-country limits on green cards. In 2007, Mr. Grassley slipped an amendment into a spending bill that would tax businesses that hire skilled immigrants an additional $3,500 per visa. And in 2009 he co-authored legislation with Democratic Sen. Richard Durbin that would have made it more difficult for U.S. companies to hire foreign workers.

Mr. Sessions, for his part, has focused on curtailing the legal migration of lower-skilled workers. He has opposed expanding the H-2b visa program for short-term seasonal jobs not in agriculture. In 2006 and 2007, he led efforts to kill a guest-worker program that would have allowed future immigrants to enter the country legally. The senator said at the time that he was worried about “how many people will come in” legally and that “all those workers are able to become permanent residents and citizens in short order.”

It is hard to figure out why, if not playing to some segment of the right-wing base, these two senators should be so anti-immigrant. Iowa has the fifth lowest unemployment in the country (4.9 percent). While higher, Alabama (7.2 percent) is still doing better than the national average. Moreover, neither of these states are overflowing with immigrants. Iowa’s Hispanic population (immigrant and otherwise) is a mere 5 percent, while Alabama has only 3.9 percent. In short, their insistence that they are pro-immigration is false and their opposition is hard to justify by objective factors affecting their states.

The other line we hear from immigration exclusionists is that whatever border enforcement is in place, it isn’t enough. Never mind that the same enforcement mechanisms (a fence, technology deployed at the border, E-verify) have been part of exclusionists proposals for years. As we saw with Sen. Ted Cruz (R-Tex.) yesterday, concern about enforcement is often a front for refusal to tolerate legalization.

Today, Rubio argued in an interview that the Gang of Eight is strong on enforcement:

So for example, one of the things we’ve known for a long time is that the magnet that draws illegal immigrants to the United States is employment. And this law mandates a universal E-Verify system. It is not an option, it is a mandate. They must do it. We know that 40 percent of the people that are illegally in this country entered legally and overstayed their visas. This law mandates the creation of an entry and exit system so that we can track everyone, not just when they come in, but when they leave. It also mandates spending over five-and-a-half billion dollars on border security, including a billion-and-a-half on new fencing. Double fencing. Not chicken wire, I mean real stuff.  So these are mandated things that will have to happen.  . . . The alternative to doing that, I think — unfortunately, given the political make-up of the country — is to leave things the way they are and to leave them in place. And the way they’re in place right now is an administration that is never going to do E-Verify, that is never going to secure the border, and is never going to do any of these things that we’re talking about doing.

Asked if the Obama administration wouldn’t just cheat on the enforcement, he replied:

This law doesn’t even get to the first trigger point until year five. Let me say, E-Verify isn’t a discretionary thing. It must be done. Entry/Exit in this bill is not discretionary, it must be done. The only thing that they get a chance to do is this border stuff. They have to come up with a plan to secure the border, and a plan for the fencing. And in five years — that means two years after she’s long gone — if they are not apprehending 90 percent of the people crossing the border, then an additional $2 billion will be spent on border security. This is long after they’ve gone away. And so, listen, there are always going to be consequences for having the wrong people in government, but the good news is, the wrong people that are there now will not be there forever. And this bill doesn’t even begin to award green cards — and not even award green cards, but allow people to apply for green cards — until year eleven. Until the beginning of year eleven, long after they’re gone.

Indeed, it is remarkable that immigration advocates have gone for this. But asking the bill to turn the Obama administration into competent executive enforcers of the law really isn’t fair — nor is it a legitimate criticism of the legislation.

More adeptly, Rubio challenged the opponents to come up with better enforcement measures: “I’ve never said that our bill was a take-it-or-leave-it offer, I’ve said it’s a starting point. If there is a better way, I’m open to it. I encourage it.  . . . I’m actively engaged and meeting with each of my Senate colleagues in the Republican Party here on a way to improve our ideas, and if we can do that, I think we should do that.”

The way to handle disingenuous opponents is to challenge them on the facts and force them to come up with a better alternative if they find the current bill insufficient. If they don’t do the latter, then they can be ignored. If they do come up with something, all the better and the bill can be improved.

Rubio and other advocates for the Gang of Eight are playing it smartly: Don’t let the opponents win on semi-truths and out-and-out misrepresentations.