Well only 2% of those on the watch list would qualify to own a gun, being on the watch list is in itself not a disquailfier becuase its not against the law.
Where's your evidence that only 2% would qualify? It seems to be a much bigger percentage than that. And really, how can you defend that the 2nd amendment trumps being on a no fly list, member of a terrorist organisation or being on a terrorist watch list? It would be the same as allowing pedos to work in schools. Seriously if you can be banned from flying as you are deemed a risk to blowing the plane up or hijacking it and be a full time member of ISIS and you think its still perfectly fine for them to buy and own assault weapons or their "2nd amendment rights" are being infringed then there is no hope of stopping mass shootings and the US deserve everything they get. Why aren't people in jail allowed to carry guns then? Surely they have as much right as terrorists to legally own guns?
In a 2010 report, the Government Accountability Office noted that "Membership in a terrorist organization does not prohibit a person from possessing firearms or explosives under current federal law," and individuals on the No Fly List are not barred from purchasing guns.[25] According to GAO data, between 2004 and 2010, people on terrorism watch lists—including the No Fly List as well as other separate lists—attempted to buy guns and explosives more than 1,400 times, and succeeded 1,321 times (more than 90% of cases).[26]
Senator Frank Lautenberg of New Jersey repeatedly introduced legislation to bar individuals on the terror watch lists (such as the No Fly List) from buying firearms or explosives, but these efforts have not succeeded.[25][26][27] Senator Dianne Feinstein of California revived the legislation after the November 2015 Paris attacks and President Barack Obama has called for such legislation to be approved.[25]
Republicans in Congress such as Senate Homeland Security Committee chair Ron Johnson and Speaker of the House Paul Ryan oppose this measure, citing due process concerns and efficacy, respectively.[25] Republicans have blocked attempts by Democrats to attach these provisions to Republican-backed measures.[28]
The American Civil Liberties Union has voiced opposition to barring weapons sales to individuals listed on the current form of the No Fly List, stating that: "There is no constitutional bar to reasonable regulation of guns, and the No Fly List could serve as one tool for it, but only with major reform."[29] Specifically, the ACLU's position is that the government's current redress process—the procedure by which listed individuals can petition for removal from the list—does not meet the requirements of the Constitution's Due Process Clause because the process does not "provide meaningful notice of the reasons our clients are blacklisted, the basis for those reasons, and a hearing before a neutral decision-maker."[29]
In December 2015, Feinstein's amendment to bar individuals on the terror watch list from purchasing firearms failed in the Senate on a 45-54 vote.[30] Senate Majority Whip John Cornyn of Texas put forth a competing proposal to "give the attorney general the power to impose a 72-hour delay for individuals on the terror watch list seeking to purchase a gun and it could become a permanent ban if a judge determines there is probable cause during that time window."[30] The measure, too, failed, on a 55-45 vote (60 votes were required to proceed).[30] The votes on both the Feinstein measure and the Cornyn measure were largely along party lines.[30]