Two days after President Trump assumed office he is fulfilling a campaign promise to secure America's Southern border. Sources informed us on Monday that military units were receiving orders to deploy to the region. The specific units are not yet known, but the orders are consistent with the federal government's constitutional requirement to repel foreign invasions.
Article IV, Section 4
The United States shall guarantee to every State in this Union a Republican Form of Government, and shall protect each of them against Invasion; and on Application of the Legislature, or of the Executive (when the Legislature cannot be convened) against domestic Violence.
How the forces will operate and whether they will be armed is unknown.