In order to declare Martial Law and the "temporary" and "necessary" suspension of the US Constitution, there will have to be another major incident that's for sure, most likely of the "homegrown" terrorist sort since that would "justify" all kinds of draconian bullshit.
I just don't believe any new plot where an FBI agent, infiltrator or informant supplies the bombs and guns and rah-rah determination to pull it off.
This new one is looking like most of the other "plots" "foiled" by the FBI who've been steering and providing material support to these guys for a while now it seems.
http://www.salon.com/2011/11/02/fbi_...men/singleton/
http://www.salon.com/2010/07/06/fbi_...ots/singleton/
http://motherjones.com/special-repor...ist-informants
:D