The problem with assuming the constitution will prevent Trump and the Republican controlled (despite a 9-13% approval rating, just to show how fucked the system is) congress from going full on fascist is that that requires the checks and balances the system was designed to have to be working as intended. As it stands, within four years, there is a VERY good chance, I'd say more likely than not, that the entire federal government and the majority of state level governments will be under Republican control. The checks and balances are gone. We're in for a very rough probably four and likely eight years.
Very good chance?
The Republicans control the Presidency. They control the House of Representatives. They control the Senate. They control the Governorship and both houses of the state legislature (the lone house for Nebraska) in Alabama, Arizona, Arkansas, Florida, Georgia, Idaho, Indiana, Iowa, Kansas, Kentucky, Michigan, Mississippi, Missouri, Nebraska, New Hampshire, North Dakota, Ohio, Oklahoma, South Carolina, South Dakota, Tennessee, Texas, Utah, Wisconsin, and Wyoming. They will control at least one of those bodies in Alaska, Colorado, Illinois, Louisiana, Maine, Maryland, Massachusetts, Minnesota, Montana, Nevada, New Jersey, New Mexico, New York, North Carolina, Pennsylvania, Vermont, Virginia, Washington, and West Virginia.
They're already there.