By now you have probably heard about President Trump’s intent to declare a state of national emergency under the 1976 National Emergencies Act in order to build a wall across the southern U.S. and Mexican border.

Here’s exactly what a president can do in a state of national emergency:

The Constitution does not expressly grant any powers to a president within a national emergency, but the 1976 National Emergencies Act, which Trump is citing as his source of authority here, does. Within the NEA, Congress delegates at least 136 distinct powers to the president during a state of emergency. Thirteen of these powers need a declaration from Congress, but the other 123 can be declared by the president without any say from Congress. Because emergency powers are meant to give the government a ‘boost’ of power, so to speak, they are dramatic in scope, ranging from a suspension of all laws that regulate chemical and biological weapons, to ordering military construction projects, to seizing privately owned ships or sea vessels.

The NEA was initially intended to reign in the president’s national emergency powers. Under the NEA, the president was supposed to specify in his declaration of emergency which powers he intended to use, update the public on any changes or additional powers, and make an expenditures report to Congress every six months. The state of emergency would expire after a year unless the president renewed it, and both the Senate and the House of Representatives would have to meet every six months during the emergency to vote on terminating it or not.

But the NEA has not panned out as its writers intended. No less than thirty separate states of emergency are still in effect today, having been renewed over and over for years on end. Nor has Congress met anytime during the forty years of the NEA’s time in place to vote on terminating any of these states of emergency. Due to this drastic oversight on Congress’ part, President Trump has access to 123 powers enumerated in the NEA, as summarized by the NYU School of Law.

He could deploy troops within the United States at the request of a state’s governor or legislature to suppress insurrection within that state, as well as unilaterally deploy troops if he determines ‘rebellious activity’ as made it impracticable to enforce federal law regularly, or because he deems it necessary to suppress ‘insurrection, domestic violence, unlawful combination, or conspiracy’, as outlined in the Insurrection Act of 1807. These terms- insurrection, domestic violence, etc.- are not defined in the Insurrection Act, and are therefore free for interpretation by the president. Former presidents who have used the Insurrection Act to deploy troops on their own soil include Harry Truman in 1957 when he used it for school desegregation in Arkansas, George H. W. Bush in 1992 to stop riots in Los Angeles, and very nearly George W. Bush in the aftermath of Hurricane Katrina, though he decided against it when the governor of Louisiana resisted it.

He could also potentially seize control of portions of U.S. internet traffic under an amendment of Section 706 of the Communications Act of 1934, which allows the president to shut down/seize control of ‘any facility or station for wire communication’ upon a declaration ‘that there exists a state or threat of war involving the United States’. At the time of the amending, in 1942, ‘wire’ meant telephone calls, government officials recently endorsed a reading of the Act as applicable to cybersecurity. If that interpretation held, Section 706 could be used against social media outlets, news websites, search engines, email, computers systems or perhaps even Bluetooth devices connected to the Internet.

In short, the NEA is filled with powerful words that are undefined- except at the president’s discretion- and vague terminology that could be interpreted to mean harm or good for the public at large, depending on how the president chooses to wield it. In a state of national emergency, the powers of the executive branch are not held in check by Congress like usual, and it comes mostly down to the judicial branch to balance out the governmental system. One of the most powerful tools we always have, even in distressing political times like these, is our voices. Finding a group or rally to join, or talking with others on social media, is a great way to make your opinions known and speak up to the government, letting them hear the people’s voices.