Leaving aside the astronomical odds against something to happen so are almost an impossibility ASB level ... He would be closer to their actions as President model, given his character and used to exercise his will without moral restrictions or of any other serious guy like Mussolini and violently politically ruthless and charismatic as Hitler but without any of his organizational qualities and shrewdness politics.
...More seriously: he won't stay president long enough to do anything. A battalion of US Marines will come for his ass, like they did for Noriega in Panama.
For reasons that I explained in a similar thread I doubt very much that even the idea of a military intervention is contemplated to depose a Latin American president although this is Pablo Escobar Gaviria.
USA had and still has more effective and indirect methods to intervene and influence in Latin America in addition to whatever happens in Colombia could hardly be a threat to US national security of such magnitude that requires mobilizing the US Army to start a war against Colombia.
Finally, it is not underestimating as fighting force that are the US. Marines, but only one battalion? ... Must remember before to post, that Colombia isn't a small, almost helpless, State governed by a cowardly and inept little dictator as was the case of Panama nor the Marines are not all-powerful supermen-style Warhamer Space Marines !!!