Despite a Democrat who felt the bill is 'Islamophobic', (Rep. John Conyers (D-MI)) the bill got passed up to the next level for consideration.
Designating the Muslim Brotherhood a terrorist group would be a highly significant event, not to mention require considerable changes at the White House with a lot of senior staff, as well as possibly within the DHS.
It would likely also mean the restarting of the Holy Land Foundation Trial along with the reintroduction of cases of documents discovered in a police search of a hidden sub-basement in Virginia, that would reveal a significant amount of uncomfortable facts and ambitions of the Brotherhood, and which Obama may have sealed and some allege that Holder's DoJ, and Obama may have even stopped the trials.
For a comprehensive course on Muslim Brotherhood penetration in America, please see this 10 video course from Frank Gaffney's Center for Security Policy.
The CSP also has this article about today's Judiciary Committee approval.
Lastly here is a briefing by Stephen Coughlin in Ottawa Canada Sept. 2015 which deals with the Muslim Brotherhood and their ambitions for Western Civilization.