Robert Chesney, looking at the trial of Mahamud Said Omar, a Minnesota resident who is accused of aiding Somali terrorist group Al Shabaab, cites it as an example of a case in which military commissions simply can't be used:
The case is not unlike the much-discussed (and frequently critized) Warsame scenario, in that it involves a Somali man engaged in supporting al-Shabaab. To be sure, Warsame was also linked to AQAP, whereas there is no such claim so far as I know as to Omar. But on the other hand, Omar allegedly was involved quite directly in the infamous–and quite successful–recruitment of young Somali-American men from the Minneapolis region. In any event, the first important thing to note about the Omar case is that there almost certainly was no alternative to charging him in civilian court. He was arrested in the Netherlands, after all, and as we saw previously with the Delaema case, the Dutch are not likely to extradite if we plan to hold someone in military detention or use a military commission. This alone ought to be enough to stop Congress from passing legislation that would categorically bar civilian prosecution in all cases where military detention or a commission proceeding might also be a possibility.
Al Shabaab is affiliated with al Qaeda but hasn't attacked the U.S., so there's a question as to whether he'd be covered under the AUMF anyway. But I'm not sure that this will change too many minds in Congress--bringing alleged terrorists to American soil for trial wasn't a problem during the Bush administration, and it's not clear to me that it's motivated by a genuine concern about public safety given the hundreds of convicted terrorists captured on American soil rather than keeping Guantanamo open at all costs. Republicans just don't have a whole lot of political reasons for changing their minds on this.