This will never work. It astounds me that there are Senators who are so clueless on issues that are so important.
Giving the benefit of the doubt that there may be people who could use a little bit of extra scrutiny for whatever reason... the policy of the DHS is to not tell them that they are on a list, or under some form of surveillance, etc... So what happens if you deny these folks the ability to buy a gun? If they are otherwise eligible, it won't be hard to figure out they're on "the list."
The last two paragraphs of the article sum it up:
Every time someone tries to buy a gun in the U.S., the background checks include the terror watch list. When there is a match, the information is shared with the FBI case agent who is leading the terrorism investigation, according to a counterterrorism official who spoke on condition of anonymity in order to discuss the process.
To deny all people on the watch list from purchasing a weapon would mean the government would have to tell someone he or she is on the list. A person who knows he is on a watch list could change his behavior or even his identity to avoid detection, the official said.
What Lautenberg is literally doing is trying to push his fear of guns to a higher priority than what should be a legitimate effort to keep terrorists from blowing things up and killing people.
How can you get it any more wrong than that?