Sen. Marco Rubio (R-Fla.) is playing it smart on the Gang of Eight plan. Immigration exclusionists are playing a familiar game — imagine scenarios in which terrible things will happen if the bill passes and claim that the bill, therefore, is a no-go. Rubio is responding in two ways, both designed to lessen conservative opposition to the bill.

On out-and-out falsehoods, his team has been setting out a blizzard of “Myth vs. Fact” e-mails and posting them at his Web site on everything from access to federal benefits, border security, proof of residency requirements and impact on U.S. workers.

The central claim of opponents  — that there is no real border security — is the most common complaint and should, logically, be easier to rebut since the current situation effectively entails no border enforcement. Still critics keep bringing it up, and Rubio keeps batting down their gripes by pointing to the improvements in funding, staffing and workplace e-verification to cut off the flow (which isn’t flowing anymore due to the economy and the dropping birthrate in Mexico) of immigrants crossing illegally.

Rubio on a talk show radio responded to the border issue most recently by conceding people are concerned about the government enforcing existing law. He was swift to point out what he called “exaggerations” (e.g. claims that the secretary of homeland security can waive the whole thing). But his central point was this:

I understand how things have been done in the past in Washington, where they come up with a bill in a room and then they basically tell everybody, ‘Here’s the solution. Take it or leave it.’ That’s never what I signed up for. On the contrary, the way I think you’re supposed to make public policy in this country is you file a bill as a starting point, but you don’t pretend you have all the answers to every question, and then you get input from others. Now, what I have suggested to those who have problems with some component of the bill is, you know, maybe you have a very valid point. In fact I’ve heard some valid objections. Let’s try to fix it. Let’s try to change it, but to just say let’s defeat the whole thing, I don’t think that’s a productive approach either. I think this is a starting point that obviously we can and should improve.

Ah, there’s the rub. If the concerns about, for example, the timing and soundness of the triggers to allow green card status aren’t to opponents’ liking let them come forward with something. Negotiations 101 tells you never to bargain against yourself; Rubio should continue to challenge those with concerns to fix the perceived problems. And he might consider some public debates or TV panels going face to face with opponents. When forced off their talking points and chided for their misrepresentations, immigration reform opponents may find it tough sledding.

There are a couple benefits to Rubio’s strategy. First, it will reveal those who have no interest in any bill. Second, it will make the bill stronger and thereby more resistant to attack. Rubio can be disarming in his agreeableness and willingness in public to assume his opponents are operating in good faith. His mettle will be tested, however, when it becomes evident that some conservatives aren’t.

A final point is key here. The more impossible the right’s demands the more reason has Rubio and other avid proponents of immigration reform to seek votes from Democrats. That will make the bill “weaker” from the perspective of conservatives. The same dynamic played out in the 2011 budget negotiations and again in the fiscal cliff (“Plan B”) when conservatives zapped a solid conservative proposal, only to see the bill get worse.

Meanwhile, the president is doing the most he can for immigration reform, which means generally keeping quiet. Considering how he rubs Republicans the wrong way, that’s very helpful to Rubio.