start an imperialist war with mexico, then canada, and proclaim The Great North American Empire

I'll tell you what I'd do, man: two chicks at the same time, man.

I would run the US like BBV.

disband the legislative and judicial branches of government

legalize all drugs

3 years mandatory national service at age 18

grant full citizenship to any immigrant who serves 3 years in military

raise corporate tax rate and top bracket income tax

institute national health system and reopen all the shuttered insane asylums

nationalize the gun companies and issue strict control

outlaw state militias

institute immediate death penalty for a wide range of crimes

flatbed trucks with guillotines roam the streets to suppress dissent

outlaw private schools

limit public expression of religion, and teach humanism in all schools

close down military bases around the world and focus on restoring the contiguous American landscape

free broadband internet for all

pay every adult citizen $30k/year in return for "keeping it real". if you commit a crime: you lose your head in the basket, no more 30k, that's the tax for not keeping it real.

kill everybody

I'd stop pardoning Thanksgiving turkeys.

I would obviously abuse my powers and get myself impeached.