Not much it appears.

Salmon and a few other conservatives are the only ones saying it publicly so far, but the reality is that a department shutdown would have a very limited impact on national security. That’s because most department employees fall into exempted categories of workers who stay on the job in a shutdown because they perform work considered necessary to protect human life and property. Even in a shutdown, most workers across agencies, including the Secret Service, Transportation Security Administration, Federal Emergency Management Agency and Customs and Border Protection, would continue to report to work. Airport security checkpoints would remain staffed, the Secret Service would continue to protect the president and other dignitaries, the Coast Guard would stay on patrol, immigration agents would still be on the job.

Indeed, of the agency’s approximately 230,000 employees, some 200,000 of them would keep working even if Congress fails to fund their agency. It’s a reality that was on display during the 16-day government-wide shutdown in the fall of 2013, when national parks and monuments closed but essential government functions kept running, albeit sometimes on reduced staff.

In other words, the cries of disaster, mostly from Democrats and from a few in the wimpy Republican leadership, are the same bull we heard prior to sequestration and the previous government shutdown. From a political point of view, the Republicans have nothing to lose politically by letting this agency run out of funds, and everything to gain.