Florida GOP Sen. Marco Rubio seems well meaning enough. As second-generation conservative Americans, I know we both share a common passion for this great land of opportunity. But when it comes to comprehending the real agenda of the open-borders zealots he's allied himself with, Rubio doesn't have a clue.

And his abject ignorance threatens all of us who cherish American sovereignty and exceptionalism.

On Fox News' "The Sean Hannity Show" Tuesday night, Rubio defended his Gang of Eight "immigration reform" bill and insisted that we could and should have a system in place that vets foreign tourists and short-term visa holders based on their "national security" profiles.

"In essence, we should be able to analyze (whether) these are individuals coming from a part of the world that keeps feeding into the terrorist network," Rubio earnestly explained. "(W)e should be very careful about who we allow in and take into account every single measure or every single factor that we think could lead to somebody being more likely possibly a member of a terrorist organization or involved in terror."

Great idea, Rubio! Newsflash: The concept of a national security entry-exit screening database is at least 10 years old. It's an idea that was sabotaged by the progressive soft-on-security ideologues with whom Rubio has recklessly partnered.

In the immediate aftermath of the 9/11 terrorist attacks, the Bush administration created NSEERS, the National Security Entry-Exit Registration System. Administered and championed by Justice Department constitutional lawyer, immigration enforcement expert and now-Kansas Secretary of State Kris Kobach, NSEERS stopped at least 330 known foreign criminals and three known terrorists who had attempted to come into the country at certain official ports of entry.

NSEERS required higher scrutiny and common-sense registration requirements for individuals from jihad-friendly countries including Afghanistan, Indonesia, Iran, Iraq, Jordan, Libya, Pakistan, Saudi Arabia, Somalia, Syria and Yemen, as well as other at-risk countries. The basic components included a more rigorous application process in light of the shoddy visa questionnaires and undetected overstays of the 9/11 hijackers; 30 extra minutes of interviewing at ports of entry; a digital fingerprint check and in-person registration after they arrived in the interior of the country; and verification of departure once they exited.

The targeted registration of certain foreign nationals already in the country (temporary visa holders including students, tourists and businesspeople) resulted in the apprehension of dozens of illegal alien felons. As I reported at the time, these scumbags included:

--a Tunisian convicted of multiple drug-trafficking offenses, in addition to previous violations of immigration law.

--an Iranian who had been convicted three times of assault with a deadly weapon and had been convicted twice of grand theft in addition to immigration violations.

--an Iranian twice convicted of child molestation.

--two suspected al-Qaida operatives who were caught trying to enter the U.S. after their fingerprints matched ones lifted by our military officials from papers found in Afghanistan caves.

But grievance-mongering identity groups and the American Civil Liberties Union could not stand the idea of an effective national security profiling database. For one thing, a successful program would have laid the groundwork for a broader nationwide entry-exit system affecting all foreign visitors. Congress mandated that system six times over the past 17 years. It has yet to be built.

Let me repeat that: We still have no way of tracking who has actually met their visa requirements, who has overstayed their visa, and who has left the country when their visa requires them to do so. Earth to Rubio: This malignant failure is by special-interest design, not by accident or lack of imagination.

Here's a test: Why doesn't Rubio form a Gang of One and dare Washington to pass the entry-exit system his new pals all say they support as a stand-alone first. Let's see them prove they can keep even a single one of their national security/immigration enforcement promises before entertaining 900 more pages of them. Prove it.

I've read the bill -- and I can see right through it. The Democrats' history speaks for itself. The late Sen. Ted Kennedy, whose illegal alien amnesty spirit infuses the Gang of Eight's bill, spearheaded legislative attempts to de-fund and destroy NSEERS. His left-wing pals (and a few open-borders Republicans such as heavyweight operative Grover Norquist, who stood literally and figuratively behind Rubio at the amnesty bill unveiling) decried NSEERS and its supporters for fostering "discrimination" and "profiling."

Never mind that the pilot program was in line with alien registration systems around the world. And never mind that indiscriminate entry and immigration policies are what enabled so many jihadi plots in the first place.

When the Obama administration took over, as Kentucky GOP Sen. Rand Paul pointed out this week, it indefinitely suspended the NSEERS pilot program and has no plans to revive it in the aftermath of the Boston Marathon bombings.

Now the Gang of Eight Republicans want conservatives to jump in bed with these security saboteurs for another Amnesty Now, Enforcement Never plan? Who's Rubio kidding? Only himself.