One of the officials of our current administration,and I do not recall which one,said something about always exploiting a crisis to get something done that would otherwise be impossible.
That was Rahm Emanuel, "Never let a serious crisis go to waste".
He was echoing many people who've said the same thing before or accused others of the same thing. ie Bush and 9/11, Johnson with the Gulf of Tonkin, Kennedy and the missile gap, or Palmer and the post WWI Red Scare.
imho the Columbine tragedy signaled the end of gun controls ability to use a crisis to advance their agenda in any meaningful way. Following the event there was a very strong movement for greater restrictions on gun ownership. That movement died with a whimper.
On the other hand many other rights have been greatly degraded over the last few decades. The drug "crisis" started the degradation of the 4th amendment and the war on some terrorists pretty much killed it.
The 1st amendment has been up and down like a yo-yo since the US was founded. Now is a real down time. Ari Fleischer pretty much summed it up when he said "people should watch what they say".
Of all the Bill of Rights it seems like only the 3rd is safe from encroachment.